Your Pregnancy Week-by-Week Guide

Team Peanut12 months ago15 min read

Congrats on your pregnancy, mama! While your body is busy building a baby, we’ll keep you up-to-date on your journey from bump to birth.

pregnancy week by week

From early symptoms and feeling that first kick to baby’s size and weight, find out what to expect during pregnancy with our detailed pregnancy week-by-week guide.

First Trimester

Baby at 9 weeks

Weeks 1-2

First trimester of pregnancy: If you’ve just found out you’re expecting, you might think this is your first week of pregnancy…

Turns out, you’re probably around four weeks pregnant!

Simply put, day one of your pregnancy is calculated as the first day of your last period, so at one week pregnant you’re actually not pregnant at all (yep, really!).

🔎 Dig deeper:
1 week Pregnant: What to Expect
2 weeks Pregnant: What to Expect

Week 3

Although it might seem like nothing is happening on the outside - on the inside, you’ve made a baby!

You recently ovulated and a fertilized egg is sitting happily on the wall of your uterus, gearing up to grow over the next eight months.

🔎 Dig deeper:
3 Weeks Pregnant: What to Expect

Week 4

Congrats, mama!

Your developing baby is now officially an embryo, and is the size of a poppy seed (cute!).

You may not be feeling any different just yet, since early pregnancy symptoms don’t always kick in right away, but you can always try a home pregnancy test.

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4 Weeks Pregnant: What to Expect

Week 5

By week five, you should’ve missed your period - one of the most obvious signs of pregnancy.

Also, at this point, the level of hCG in your body (aka the pregnancy hormone) is definitely high enough to be detected by a home pregnancy test, so if you haven’t had one so far - try now!

Once you’ve had a confirmed test, go ahead and call your doctor to schedule your first prenatal appointment.

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5 Weeks Pregnant: What to Expect

Week 6

At week six, baby’s heart is beating, and their fingers, toes, nose, mouth, and ears are beginning to form - although, they look a lot like a teeny tiny tadpole right now with a head and a tail!

You might find that you’re running to the bathroom a lot more than usual, feeling bloated, queasy, and fatigued.

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6 Weeks Pregnant: What to Expect

Week 7

Only seven months left to go until you’re holding your baby in your arms!

This week, they’re growing bigger, stronger, and smarter by the second as new brain cells are being developed at a rate of 100 per minute.

You might be experiencing morning sickness (which, by the way, doesn’t just happen in the morning!) as well as achy breasts.

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7 Weeks Pregnant: What to Expect

Week 8

Way to go - your placenta is now fully functioning and your baby is about the size of a raspberry!

This week, they’ll double in size and their major organs will continue to grow and develop.

By now, your clothes might start feeling a little snug.

That’s because your uterus, which is usually the size of a fist, has grown to the size of a large grapefruit.

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8 Weeks Pregnant: What to Expect

Week 9

All of your baby’s essential organs have begun to develop, and their muscles, and toes and starting to appear.

At this point, they’re looking less tadpole-like and more like a human (scroll back and see the image at the top!).

At week 9, your pregnancy symptoms are pretty severe (think: peeing seventeen thousand times a day and feeling exhausted 24/7).

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9 Weeks Pregnant: What to Expect

Week 10

This week, your baby’s about the size of a prune, and their fingers, toes, and nails are growing and bones and cartilage are forming.

Week ten might be a good time to pull out those comfortable dresses and stretchy jeans too, as your bump might be beginning to show (don’t worry if it isn’t!).

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10 Weeks Pregnant: What to Expect

Week 11

Your little peanut’s fingers and toes have now separated - way to go, mama!

Baby is now as big as a large strawberry, their bones are hardening, and their ears have settled into their final position on the sides of their head.

Even better? Your hunger might increase now as morning sickness finally eases!

🔎 Dig deeper:
11 Weeks Pregnant: What to Expect

Week 12

You’ve reached the home stretch of the first trimester (finally!) which means baby has developed most of their important organs and their job from now on is to keep growing.

Although they’re busy moving around inside you, you won’t be able to feel a thing just yet.

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12 Weeks Pregnant: What to Expect

Second Trimester

Baby at 19 weeks

Week 13

Welcome to the second trimester!

Your baby’s vocal cords are starting to form and their head is about half the size of their body right now.

You might notice that you’ve gained a little bit of weight, which is totally normal, and although morning sickness may still be lingering, it won’t stick around for much longer (fingers crossed!).

🔎 Dig deeper:
13 Weeks Pregnant: What to Expect

Week 14

By week 14, your baby is sprouting a thin, peach fuzz-like hair all over their body called lanugo that helps keep their body warm - fetal development is neat, huh?!

This week you also might start experiencing sharp pains on the sides of your stomach, but don’t worry, these are called round ligament pains and are nothing more than your body adjusting to growing a tiny human.

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14 Weeks Pregnant: What to Expect

Week 15

Your baby is flipping and flopping around inside you and you might even begin to feel it!

They’re currently as long as four inches, the size of a pear, and focusing on strengthening their bones.

Next up on the list of pregnancy symptoms for you?

Increased sex drive, and not-so-lovely heartburn.

🔎 Dig deeper:
15 Weeks Pregnant: What to Expect

Week 16

Baby is now the size of an avocado and their circulatory system is working hard to pump blood.

They can now make sucking motions and their eyes are sensitive to light, but they’re still closed.

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16 Weeks Pregnant: What to Expect

Week 17

Speak up, mama, as baby can now hear you.

They’re currently over five inches long and working on perfecting their sucking and swallowing skills as they get ready for the real thing: a breast or bottle!

At this point in your pregnancy, you might start noticing faint stretch marks, a pregnancy souvenir.

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17 Weeks Pregnant: What to Expect

Week 18

Around week 18 you might get to see your little one on an ultrasound.

They’re now able to yawn, hiccup, twist, roll, and kick - which you might be able to start feeling over the next few weeks.

Plus, baby now sleeps and wakes throughout the day and is responsive to loud noises outside of the womb.

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18 Weeks Pregnant: What to Expect

Week 19

Your baby is about the size of a mango now and their kicks are getting stronger.

They’re also forming vernix, a waxy covering that protects their skin from amniotic fluid.

At 19 weeks pregnant you’re probably experiencing new aches and pains, like leg cramps, backache, or a stuffy nose - which are all completely normal.

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19 Weeks Pregnant: What to Expect

Week 20

You’ve reached the halfway point!

It’s likely that you now know whether you’re having a boy or girl (if you opted to find out!) or you’ll be discovering this soon.

Baby is now the size of a sweet potato, so you may have to start fighting off random strangers who insist on feeling your pregnant belly (no, this is not OK!).

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20 Weeks Pregnant: What to Expect

Week 21

By week 21 there’s a good chance you’ve felt baby’s first movements - if you haven’t, don’t worry, it might take a few more weeks for you to pinpoint those first kicks.

They’re certainly trying to show you they’re there, though, as they squirm around and move their fully formed fingers, toes, and fingerprints!

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21 Weeks Pregnant: What to Expect

Week 22

Baby is now about 11 inches long - as big as a red bell pepper!

Their tear ducts are starting to develop as they continue to move their eyes around underneath their eyelids, and their taste buds continue to develop rapidly.

As your stomach continues to expand, you might notice that your feet are getting a little bigger too, but don’t worry, this is totally normal.

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22 Weeks Pregnant: What to Expect

Week 23

Your baby is starting to learn your voice, so continue to talk (or sing!) to them when you can.

The placenta is working hard to transfer oxygen, nutrients, and remove waste products as your baby continues to grow.

This week, you might notice the sudden appearance of a dark line running from your belly button, this is called linea nigra and it’ll eventually fade.

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23 Weeks Pregnant: What to Expect

Week 24

As your baby’s muscles continue to grow, they’re putting on more weight, growing more hair, and their lungs are fully formed (way to go!).

This week, you might notice your former innie belly button is now an outie, and that your ankles and feet are swelling - things will return to normal after delivery!

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24 Weeks Pregnant: What to Expect

Week 25

Baby is now as big as an eggplant and no matter what their skin color will eventually be, it’s turning pinker now.

Plus, their nose starts working this week, allowing your little one to start taking practice breaths (well, breaths of amniotic fluid).

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25 Weeks Pregnant: What to Expect

Week 26

Eyelashes are growing, fingernails have officially arrived, and your tiny gymnast is starting to run low on room in your uterus as they practice their acrobatics.

Their eyes are finally open and they can respond to noises they hear with an increase in heart rate or movement.

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26 Weeks Pregnant: What to Expect

Week 27

Your uterus is now the size of a basketball, and inside your baby is the size of a cabbage and more than a foot long.

You might find that this week your new outie belly button starts to protrude even more, and you start to experience insomnia.

🔎 Dig deeper:
27 Weeks Pregnant: What to Expect

Third Trimester

Baby at 39 weeks

Week 28

Welcome to the third trimester!

Hang in there, mama.

Your baby can dream, blink, and make faces inside your womb now.

Even if you’re uncomfortable, swollen, can’t sleep, and your back aches, know that you’re doing an amazing job growing a healthy baby!

🔎 Dig deeper:
28 Weeks Pregnant: What to Expect

Week 29

Your womb is getting pretty cramped at this point so those flips and kicks are now uncomfortable jabs and pokes from little elbows and knees.

You might find that you can barely see your feet when you’re standing too, and you’re probably down to just a few outfits that fit.

Not long to go!

🔎 Dig deeper:
29 Weeks Pregnant: What to Expect

Week 30

Your growing baby bump is a definite clue that your little one is getting bigger day by day.

Their hands are now fully formed, they weigh about three pounds, and the lanugo - that peach fuzz-like covering on their body - is beginning to disappear as their new fat cells regulate their body temperature.

🔎 Dig deeper:
30 Weeks Pregnant: What to Expect

Week 31

Your baby’s brain is working overtime these days and developing faster than ever, plus they can now use all five of their senses!

On a less positive note, your growing uterus is starting to push all of your internal organs elsewhere, which may leave you feeling short of breath, and desperate for the bathroom.

🔎 Dig deeper:
31 Weeks Pregnant: What to Expect

Week 32

Baby’s organs are now fully formed and their skin is no longer transparent.

They’re around four pounds and somewhere from 15 to 17 inches long.

This week, you might start experiencing Braxton Hicks contractions, but that doesn’t mean you’re going into labor, it’s just your body practicing and gearing up for the big event.

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32 Weeks Pregnant: What to Expect

Week 33

Your baby drinks about a pint of amniotic fluid each day now, which helps prepare their body for life outside of the womb.

At this point, your breasts might start leaking colostrum, a nutrient-dense milk, and your belly is likely to get increasingly itchy as it stretches. Ah, the joys of pregnancy!

🔎 Dig deeper:
33 Weeks Pregnant: What to Expect

Week 34

With just six weeks to go, your baby is as big as a pineapple and the vernix on their skin is thickening in preparation for its shedding over the next few weeks.

You’ll want to be careful this week, as you might be a little more clumsy as your center of gravity changes because of your ever-growing bump!

🔎 Dig deeper:
34 Weeks Pregnant: What to Expect

Week 35

By this week, baby is starting to prepare to exit and is likely to be positioned with their head facing down towards your cervix.

Don’t worry, their soft skull allows them to squeeze through the birth canal with ease.

Take some time to chill this week mama, as you’re probably dealing with a lot of swelling and Braxton Hicks by now!

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35 Weeks Pregnant: What to Expect

Week 36

Your baby is packing on the cuteness (literally) with chubby little arms and legs by now.

They may drop lower into your pelvis sometime soon, which may make you waddle a bit when you walk, but at least it will make more room for your lungs so you can breathe again!

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36 Weeks Pregnant: What to Expect

Week 37

By week 37, your little peanut is almost ready to make their grand entrance!

They can grasp things now, like their toes or ears, and they may even be sucking their thumb in preparation for feeding in the real world.

Don’t worry if you start to feel less movement in your womb as baby runs out of space, but you should still feel something every day.

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37 Weeks Pregnant: What to Expect

Week 38

At 38 weeks pregnant, all systems are (almost!) go.

Baby is now as big as a mini watermelon and continues to shed lanugo and vernix.

As their brain and nervous system are fine-tuned, they’re also working on maturing their lungs ready for their first breath outside of the womb.

🔎 Dig deeper:
38 Weeks Pregnant: What to Expect

Week 39

With just one week to go, your little one isn’t quite so little these days as they’ve reached their birth weight!

This week you should be watching for signs of labor, like the loss of your mucus plug, bloody show, and regular contractions.

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39 Weeks Pregnant: What to Expect

Week 40

You made it, mama!

Your baby likely weighs anywhere from six to nine pounds and measures between 19 and 22 inches.

At birth, their vision will be a little blurry and they’ll love being swaddled and hearing your voice.

Your body will know when it’s time to deliver - this week your cervix will open and thin out, and your doctor will provide measurements to give you a better idea of when you can expect to go into active labor.

🔎 Dig deeper:
40 Weeks Pregnant: What to Expect

Week 41

You’re not technically overdue until 42 weeks, so if you’re still pregnant, no need to panic!

Your doctor will keep a close eye on you and your baby’s health to make sure things are progressing smoothly.

Try to put your feet up and rest.

🔎 Dig deeper:
41 Weeks Pregnant: What to Expect

Week 42

Your due date has come and gone and you’re probably sick of everyone calling to ask whether you’ve had the baby yet.

Your doctor will continue to keep a close eye to help determine the best course of action.

Whether you’re schedule for an induction or your go into labor on your own - you’ve got this!

🔎 Dig deeper:
42 Weeks Pregnant: Almost There!

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