Every week brings new developments when you're expecting. Your baby's changing day by day, and your body is keeping pace with developments of its own. Find out what's going on, inside and out, with this week-by-week pregnancy calendar guide.
Weeks 1 and 2 of pregnancy
Your pregnancy begins as your body gears up for ovulation and prepares for fertilization.
Week 3 of Pregnancy
As sperm meets egg, fertilization occurs and your baby-to-be takes form — as a tiny group of cells.
Week 4 of Pregnancy
The blastocyst that will be your baby splits to form the placenta and the embryo, and the specialized parts of your baby's body begin to develop.
Week 5 of Pregnancy
Your baby's heart and circulatory system are developing, while your hCG hormone levels are now high enough to confirm your good news with a home pregnancy test.
Week 6 of Pregnancy
Your baby's face is taking shape, which is something sweet to think about as you race to the toilet to pee yet again.
Week 7 of Pregnancy
Right now, the only things growing faster than your baby's brain may be your tingly, achy breasts.
Week 8 of Pregnancy
As your baby starts moving in the womb, morning sickness (which doesn't just strike in the morning) may have you moving to the bathroom.
Week 9 of Pregnancy
Your baby is busy building muscle, but all you may want to do these days is take a nice long nap.
Week 10 of Pregnancy
On your baby's to-do list this week: Build bones and cartilage. On your agenda, increase your fiber intake to cope with pregnancy constipation.
Week 11 of Pregnancy
That adorable little alien inside your tummy is starting to look human about now, as you start feeling a bit more human yourself.
Week 12 of Pregnancy
While it may seem as if you've doubled in size over the past few weeks with pregnancy weight gain, it's your baby who actually has!
Week 13 of Pregnancy
As the first trimester comes to a close, your baby's about the size of peach, though you may not be feeling too peachy about your sex life right now.
Week 14 of Pregnancy
It's all about hair now as your baby sprouts some on his head, eyebrows, and body. As for Mom, those first-trimester pregnancy symptoms should be easing up a bit.
Week 15 of Pregnancy
You might not yet be feeling it, but your baby is kicking those little legs and flexing those elbows, while — higher up — you may be coping with some dental weirdness.
Week 16 of Pregnancy
Here's an eye opener for you: While you're packing onthe baby pounds, your baby's eyesight (and eyelashes!) are developing rapidly.
Week 17 of Pregnancy
Your baby is practicing sucking and swallowing as she gets ready for the real thing: a breast or bottle! As for Mom, you may be warding off some unwanted belly touching.
Week 18 of Pregnancy
You might start to feel your baby moving around anytime now, which is a great way to take your mind off your bothersome back.
Week 19 of Pregnancy
Your baby's skin now has a protective coating, while you might be hoping for something to protect you from painful leg cramps.
Week 20 of Pregnancy
Boy or girl? You can find out this week through a routine ultrasound!
Week 21 of Pregnancy
Your baby is grazing on whatever you are right now, but those stretch marks are yours alone, Mom.
Week 22 of Pregnancy
These days, the only things growing more rapidly than your baby's senses may be her mommy's feet!
Week 23 of Pregnancy
Baby is getting (a little) plumper, but Mommy may notice something completely different when she glances at her own belly: the linea nigra.
Week 24 of Pregnancy
Your baby's facial features are really filling out…and your belly button may be really popping out!
Week 25 of Pregnancy
As baby prepares to take his first breath, pesky hemorrhoids may make you swear under yours.
Week 26 of Pregnancy
Major excitement: Your baby opens her eyes! On the flip side, you might wish yours would stay closed so you could get some sleep.
Week 27 of Pregnancy
Your baby moves on to a whole new growth chart this week, while your swollen feet and ankles may need a growth chart of their own!
Week 28 of Pregnancy
Your baby has started blinking and dreaming while you may be dreaming that the pain in your derriere will disappear!
Week 29 of Pregnancy
Your baby's packing on the pounds, which look so cute on her. If only you could say the same for your varicose veins.
Week 30 of Pregnancy
Your baby's brain is getting smarter by the minute, but for Mom, the only thing that smarts right now may be heartburn pain.
Week 31 of Pregnancy
As your baby's senses increase, his mommy's breathing room decreases.
Week 32 of Pregnancy
Your baby is practicing survival skills like sucking and breathing, while your uterus is practicing some Braxton Hicks contractions.
Week 33 of Pregnancy
Your baby's immune system gets a boost, while her sleepless mommy could use a boost of energy.
Week 34 of Pregnancy
A boy baby's testicles descend this week (whoopee!), but Mom should also look out below — and above — as her vision becomes less sharp.
Week 35 of Pregnancy
A rapidly growing brain makes your baby's head weigh more and that means more pressure on Mommy's bladder.
Week 36 of Pregnancy
Your baby's bones may be ready to rock and roll, but yours may be aching something awful right now.
Week 37 of Pregnancy
Your doctor may check for labor signs, while your baby prepares for birth by sucking, turning, and breathing in the womb.
Week 38 of Pregnancy
Your baby is producing surfactant, which will help him take those first breaths while you're producing colostrum, the precursor to breast milk.
Week 39 of Pregnancy
Your baby's brain development is still in high gear, even as you may start to experience some definite signs of labor.
Week 40 of Pregnancy
It's the official end of your pregnancy — though your baby might not have gotten that memo. Hang in there!
Week 41 of Pregnancy
It's not unusual for a baby to be overdue, but you're apt to feel real labor pains at any time this week or next.
Week 42 of Pregnancy
In the rare case that your baby is truly overdue, the good news is she'll be wide-awake and ready to go once she's born.