Welcome to the beginning of a whole new life! The first trimester is a truly wonderful and amazing time. For the mom, her body will begin to go through changes to prepare for the growth and development of the fetus over the next nine months. It’s important for dad to understand this and know how to help mom as she goes through a wide range of emotional and physical changes.

Over the next nine months, your partner will experience a multitude of symptoms ranging from fatigue and constipation to imaginative food cravings and swelling in the ankles and feet.

Let’s break down the first trimester by week to get a better understanding of what’s going on and what you can do to make this process more enjoyable for your partner and yourself.

Jump to a week:
Week 1 | Week 2 | Week 3 | Week 4 | Week 5 | Week 6 |Week 7 | Week 8 | Week 9 | Week 10 | Week 11 | Week 12 | Week 13

Week 1

Okay, so the first week of pregnancy is kind of weird. Why? Well, because your partner isn’t actually pregnant … yet. Most Obstetrics and Gynecology (OB GYN) doctors begin counting pregnancy on the last day of your partner’s last period because determining the exact moment of ovulation and conception is nearly impossible to get exact.

In reality, your baby wasn’t really conceived until about the second or third week of pregnancy. By the time your partner realizes that she’s pregnant, she’s actually already about a month into the pregnancy.

So, if you just found out that you’re going to be a dad and you’re freaking out that you’ve only got nine months until your entire life changes, sorry, you’re already a month into the countdown. But don’t worry! Keep reading and you’ll be more than prepared for this awesome life journey that awaits.


In the first week of pregnancy, your partner will be having her period. This means that everyday life will continue as normal. Some of the symptoms she may experience are: vaginal bleeding, lower back pain and cramps, bloating, mood swings, and headaches.

If your partner is experiencing some of these symptoms and you are trying to conceive, it’s important that she begins trying to eat healthy and avoid unhealthy habits such as smoking and drinking alcohol and excessive amounts of caffeine. It’s also a good time for her to start taking prenatal vitamins.

What do I do?

During this first week, there isn’t anything you need to do other than be a good, supportive partner.

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Week 2

The same for week one holds true for week two – your partner is still not pregnant. Last week she had her monthly period, this week her body is experiencing a whole slew of new symptoms – each is an indicator that her body has begun to ovulate. If your partner expresses that she’s experiencing any of the symptoms below, it means that she’s in her ovulation window and it’s baby making time!


If you and your partner are trying to get pregnant, this is the week to do it. After her period, your partner will begin to notice some changes in her body. First, she’ll notice some white cervical mucus discharge, it sounds gross, but this fluid is her body’s way of helping your sperm reach her egg.

Additionally, she may experience other symptoms such as a better sense of smell, breast soreness or tenderness, pelvic pain, light spotting (vaginal bleeding), increased sex drive, and changes to her cervix.

What do I do?

This is the week you and your partner get to have a lot of fun – by which, we mean sex. If you’re looking to get pregnant, this is the week to do it. It’s recommended that you have sex every other day during her ovulation window.

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Week 3

Last week your sperm met your partner’s egg and POOF! she’s now pregnant. Okay, so it’s a little bit more complicated than that but who cares? You’re now going to be a dad!

The deal with week three is the same as weeks one and two. Your partner became pregnant only days a couple days ago, so there hasn’t been enough time for her to realize she’s pregnant so hold tight, the good news is coming soon!


Again, it’s too early to tell if your partner is pregnant by this point so chances are she isn’t experiencing any symptoms yet, either. However, some symptoms that women experience during this week include: implantation bleeding, nausea, sore breasts, darkened nipples, or a missed period.

What do I do?

If your partner experiences any of the symptoms above, encourage her to take a home pregnancy test, continue taking prenatal vitamins, and keep reading to learn more about what to expect through the rest of the pregnancy.

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Week 4

Welcome to week four! Your baby is the size of a poppy seed!

It’s still really early in the pregnancy and, depending on your partner’s period cycle, she may, or may not, have discovered that she’s pregnant yet. If she has, it’s time for you two to start calling doctors’ offices and begin booking appointments.

During her first exam, the doctors will use a urine or blood test to confirm the pregnancy.


Since it’s still very early in the pregnancy, it’s possible your partner won’t experience any symptoms yet. However, her body is creating a massive amount of hormones as it begins the process of growing your baby. These hormones can create a number of different symptoms, such as: bloating, mild cramping, spotting, mood swings, morning sickness, fatigue, and sore breasts.

What do I do?

If your partner is experiencing any of the aforementioned symptoms, there’s a good chance she’ll be spending most of her time at home either resting or not feeling well. It’s important, as the dad, to understand what she’s going through and know that you’ll probably have to start taking on some of the daily tasks around the house that your partner would normally do.

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Week 5

Your baby is currently the size of an apple seed.

Week five is usually when most women start to notice that they’re pregnant. So, if your partner didn’t show any symptoms last week, that’s okay, she will this week more than likely. This week is so common for discovering pregnancy because it’s around this time that your partner will notice that she missed her period – and she will more than likely begin noticing the symptoms if she hadn’t already.


Your partner’s body is going through a lot of changes right now. Increased hormone levels will create a lot of uncomfortable symptoms for her this week. They include: sore breasts, morning sickness, fatigue, frequent urination, cramps, and spotting.

Many women complain that the early stages of pregnancy are the worst. The good news is they get better, so, if your partner is complaining about her symptoms, you can assure her that they won’t last the entire pregnancy. In fact, most women say the first trimester is the worst.

What do I do?

Depending on the severity of your partner’s symptoms, she may need a varying level of help from you. Whether you’re holding back her hair during an episode of morning sickness, sleeping in the spare bedroom to not disturb her as she sleeps, or running to the store to get her something yummy to eat, you’ll start to have your hands full as the pregnancy continues.

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Week 6

This week, your baby is the size of a pea.

The news of being pregnant may be starting to settle in. However, while you may be experiencing a wide range of emotions from nervousness to bliss, don’t forget that your partner is going through a much different experience right now.

Her symptoms are most likely intensifying and she’s probably becoming increasingly uncomfortable. She’s almost halfway through the first trimester which, as was mentioned before, is the most miserable trimester for the mom.

Reminding her that she’s halfway through the worst of it could go one of two ways – relief that she’s that far along, or agony that she’s only half way there. We’ll let you decide which route you want to go.

This week your baby has begun to grow its circulatory system and is beginning to take on the shape of a human, sprouting little hands and feet as well as facial features such as a nose, eyes, chin, ears, and cheeks.


The symptoms this week are not much different than weeks before, they’re just intensified. Expect your partner to experience fatigue, nausea, sore breasts, frequent urination, gas and bloating, mood swings, cramping, and spotting.

What do I do?

While continuing to help your partner through her symptoms, it’s important to start writing down any questions you or your partner may have for the doctor – most doctors will want to schedule her first prenatal exam around eight or nine weeks, getting your questions down on paper will help you remember when you finally go in.

Your partner has a lot going on right now, obviously. She will undoubtedly be thinking a lot about planning for when the baby comes. You can help alleviate some questions and concerns by talking with her about it. Going over your insurance policies is a good idea too, you don’t want to be caught off guard by any surprise hospital costs.

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Week 7

This week, your baby is the size of a blueberry.

Believe it or not, your baby has more than doubled in size since last week. Your wife still won’t be showing any baby bump yet, but around this time she may begin to experience a slew of new symptoms – keep your gas tanked filled, you’re probably going to need to make a late night snack run or two!


In addition of the normal symptoms like nausea, mood swings, and cramping, this week your partner may start to notice she’s starting to break out with acne, producing extra saliva, and experiencing sudden cravings or aversions to particular types of food.

What do I do?

Your partner’s symptoms my vary from something which is hardly noticeable, and can go about her day with no problems, to DEFCON 2, and she’s hardly able to make it through the day without finding some way to alleviate the issue.

It’s important to remain flexible and willing to help her no matter what time of the day, or night, a symptom exposes itself. Now might also be a good time to read up on the types of prenatal testing available.

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Week 8

Your baby is the size of a raspberry!

Believe it or not, your partner is already two months pregnant! You’re probably wondering where the heck the time went, but this is just the beginning of some of the most exciting moments in your journey toward becoming a dad.

It’s during this week that most parents schedule their first prenatal appointment. At which, the doctor will take an ultrasound to try to determine exactly how far along your partner is so he can determine an approximate due date for your baby. If you’re lucky, you might even get the chance to see and hear your baby’s heartbeat for the first time!

If it hadn’t sunk in yet that you’re going to be a dad, it certainly will after that appointment.


Guys, if you’re known for forgetting to take out the trash, have morning breath, or exude any sort of odor what-so-ever, be prepared for your partner to hound you about these things – around eight weeks her hormones are in overdrive mode and chances are she’s exhibiting some superhuman characteristics, like an over-sensitive sense of smell.

Other symptoms she may experience this week include fatigue, sore breasts, morning sickness, cramps, spotting, and weird dreams.

What do I do?

Besides ensuring that you scrub yourself with soap in the shower and don’t forget your deodorant and brush your teeth, this week you should go to your partner’s prenatal appointment – you don’t want to miss it!

You’ll also want to start talking to your partner about whether or not you want to have a Chorionic Villus Sampling (CVS) done. This procedure determines your baby’s genetic make up and can help diagnose any potential chromosomal abnormalities, such as down syndrome, and any genetic problems, like cystic fibrosis.

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Week 9

Your baby is the size of a cherry!

This is big week for you, your partner, and your baby. First, your little one has graduated from being an embryo and is now a full-fledged fetus.

While every pregnancy and every woman is different, many women explain that around week nine they start to have difficulty fitting into their favorite pair of jeans.

This isn’t a bad thing! In fact, weight gain around this time is encouraged from doctors – the exact amount of suggested weight gain is completely dependent on your partner’s starting body mass index. If she has concerns about how much weight she’s gaining, encourage her to talk to her doctor, chances are good that the amount of weight she’s gaining are completely normal.


Even though she’s now in her third month of pregnancy, your partner’s hormones are still going at full throttle. Many of the symptoms are the same as weeks past: mood swings, morning sickness, frequent urination, and fatigue.

She may also begin to experience headaches and nasal congestion.

What do I do?

Your partner may be going on a roller coaster of symptoms this week and even though birth may seem a long way away, there are several things you can do now to help prepare for the big day.

Take the initiative and look at your wife’s company’s policy on maternity leave – see how much time she’s allowed to take off before, during, and after the birth. You should take a look at your own company’s policy to see if you’re allowed any paternity leave after the baby’s born.

Also, now might be a good time to take a closer look at both your insurance policies to see how much of the birth is going to be covered and what you’ll need to pay out of pocket – nothing’s worse than getting a surprise hospital bill after such a happy occasion.

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Week 10

Your baby’s the size of a strawberry!

At this point in your baby’s development, she is beginning to form joints, cartilage, bones, fingernails, and hair; her vital organs are also completely operational at this point. If you think that’s amazing, you’ll really be impressed that your little one is now practicing to swallow and kick her legs.

Week ten is also a critical time if you and your partner have opted in to having genetic screening done. Some of these tests include nuchal translucency, cell-free fetal DNA test, Chorionic Villus Sampling, and amniocentesis. All of these tests check for abnormalities.

If you’ve decided to get one or more of these tests done, it’s important to talk to your partner’s doctor about the risks and rewards of each procedure.


As your partner’s belly begins to expand as your baby grows, she will begin to experience symptoms related to the physical changes associated with growing a human inside her.

Some of these symptoms include: round ligament pain, growing breasts, morning sickness, mood swings, fatigue, increased vaginal discharge, and visible veins.

What do I do?

Every woman is different and responds to her symptoms differently, too. You need to be prepared to help your partner whenever a new wave of symptoms rears its head. For example, round ligament pain can be very painful – if she’s experiencing this ailment, you’ll probably need to step up and do more around the house and help her with tasks that she’d normally be able to do herself.

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Week 11

Your baby is the size of a lime!

Wow! Your little one has grown a lot over the last week. In fact, it’s not just his size which has grown, his little fingers and toes are no longer webbed and tooth buds, hair follicles, and nail beds are beginning to form as well. This little miracle of life is also growing skin, which is currently transparent but will soon gain some pigment.

Around this time you and your partner should have already scheduled a first trimester screen. If you opted in to the genetic screenings, some of those will be done at this time. The doctor will also take a blood sample from your partner to test for hormone levels.


Once again, as the baby continues to grow, your partner’s body will change to keep up with the baby. Some of the new symptoms she may experience may include: gas, leg cramps, and darkening skin. These are, of course, in addition to the normal fatigue, nausea, mood swings, and vaginal discharge.

What do I do?

If you haven’t done so already, now would be a great time to start thinking about creating a baby registry and talking with both your families about throwing a baby shower.

Also, depending on how intense your partner’s symptoms are, she may be feeling pretty miserable throughout the first trimester. The good news is most of these symptoms, or their severity, will pass in the second trimester – which makes it the perfect time to plan a short getaway, or babymoon. We’ll talk more about that during the second trimester, but right now would be the perfect time to find somewhere and something to do with your partner at some point before the third trimester begins.

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Week 12

Your baby is the size of a plum!

Great news! Your partner is almost finished with her first trimester. This is a big milestone for several reasons. First, her hormones are going to start leveling out which means she should experience fewer symptoms after this week. Second, your baby is now less likely to succumb to miscarriage, which is why many parents wait until the start of the second trimester to announce that they’re pregnant.

If your partner has an ultrasound around 12 weeks you’ll notice that most of her body’s systems are fully developed. This means from here on, all your baby has to do is grow, and grow, and grow.


As your partner’s hormones calm down, she is likely to experience less morning sickness and nausea, however, other symptoms may replace them through this final week of the first trimester and possibly in to the early stages of the second trimester. These symptoms include: increased discharge, spotting, headaches, and dizziness.

What do I do?

Now is the time for you and your partner to climb to the top of the closest mountain and shout with everything you’ve got that you are, indeed, pregnant. Sharing this exciting news should be fun! Talk with your partner about the best way to spread the word and don’t forget to be creative!

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Week 13

Your baby is the size of a lemon!

Even though your partner’s symptoms have begun to mellow out, don’t think your baby is doing the same. This week your little boy or girl has developed vocal chords, teeth, and fingerprints. Pretty impressive for something the size of a small fruit, right?

Even though the baby has grown significantly and is looking more and more like your little bundle of joy each week, it’s probably still too early to determine what the sex will be. Most doctors will make that determination around 20 weeks.

However, if you opted to have the prenatal screenings mentioned on the First Trimester page, your doctor may be able to determine the sex as early as this week!


This week, your partner will most likely feel more energetic and less nauseous. If not, these symptoms should be waning soon. Her uterus is also growing enough now that it may be larger than her pelvis which means she may be starting to look pregnant.

Other symptoms she may experience are visible veins and an increased sex drive.

What do I do?

With her new-found energy, it’s likely that your partner will be more inclined to do more and get out more. Take advantage of this; plan a weekend trip together, hit up the town, or make plans with friends – in a few short months, it may be more difficult for her to get around and do these sorts of things.

If you haven’t already, now is a great time to start telling your friends, family, co-workers, and boss your wonderful news. If you already have a child, now’s a good time to start getting him prepared for the new baby.

Also, depending on your situation, you may want to start looking at childcare options for when you and your partner go back to work after the baby is born.

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