Prenatal development: Week 3

Find out how your baby is developing in week three and learn the early signs of pregnancy, along with the importance of choosing the right doctor.

Your Body 

When your baby implants in your cushy uterine lining later in this week, you might notice a little bit of spotting. Nothing to worry about—in fact, it's your first sign of success. 

If you're feeling tired this week, or you're convinced that your breasts are achy or are already starting to enlarge, it may not be all in your head. They're both early signs of pregnancy.

You might also be having major mood swings (according to your partner, anyway—you're pretty sure you're being quite levelheaded and reasonable). This is all due to the hormones that are racing like Danica Patrick through your body. Those hormones are also responsible for the unimaginable exhaustion you might feel at all hours of the day.

That sudden urge to pee every 10 minutes is also an early sign of pregnancy. Unfortunately, you'll keep on peeing with this irritating frequency for the next 37 weeks, so load up on Charmin.

You may even experience the first twinges of morning sickness this week. Once you get that positive pregnancy test next week, you'll realize it actually wasn't your partner's driving that was making you feel queasy (and apologies will probably be in order). It certainly doesn't help matters that your sense of smell is suddenly sharper than a Labrador's and everything you get a whiff of makes you want to barf.

If you've been charting your body temp trying to peg down ovulation and you find your temperature stays high for a few days, congrats: You're probably preggo!

You're only a couple of hours pregnant, so you can't blame baby for that growing gut quite yet. Still, if you're trying to conceive, and especially if you think you may have hit the jackpot this month, this is no time to start dieting or to start an exercise program. 

If you've been hitting the treadmill already, feel free to continue working out. Aerobic exercise will actually make your pregnancy easier as long as you don't try to break any endurance records. Speaking of breaking endurance records, here are the pregnancy warnings that ought to be printed on the side of every elliptical machine: Keep your heart rate under 140 beats per minute and your body temperature below 102 (i.e., skip the midsummer Arizona triathlon). More realistically, that also means foregoing long soaks in the hot tub and staying out of the sauna for the next nine months. 

If you're not already knocking back a daily prenatal vitamin, start now. It's especially important right now to get at least 400 micrograms of folic acid per day. If the idea of swallowing those horse-sized pills makes you gag even before the morning sickness kicks in, you can try to get at least some of your folic acid through your diet. Best sources include beef liver, spinach, black-eyed peas, peanuts and orange juice. Or look for a breakfast cereal that's fortified with folic acid so you can fill your daily quota in a single bowl. 

How your baby's growing

What's going on in your womb now? A lot. Your baby-in-the-making is just a tiny ball consisting of several hundred cells that are multiplying madly. Once the ball of cells (called a blastocyst) takes up residence in your uterus, the part of it that will develop into the placenta starts producing the pregnancy hormone hCG (human chorionic gonadotropin), which tells your ovaries to stop releasing eggs and triggers increased production of estrogen and progesterone (which keep your uterus from shedding its lining — and its tiny passenger — and stimulates placental growth). HCG is the hormone that turns a pregnancy test positive; by the end of this week, you may be able to take one and get a positive result! (If your test is negative and you still haven't gotten your period in two or three days, try again then.)

Meanwhile, amniotic fluid is beginning to collect around your ball of cells in the cavity that will become the amniotic sac. This fluid will cushion your baby in the weeks and months ahead. Right now, your little blastocyst is receiving oxygen and nutrients (and discarding waste products) through a primitive circulation system made up of microscopic tunnels that connect your developing baby to the blood vessels in your uterine wall. The placenta won't be developed enough to take over this task until the end of next week.

Ovulation and Sense of Smell

Are smells suddenly stronger to you than ever? It could be a sign that you're ovulating! Scientists aren't quite sure why this happens, though it's been theorized that a heightened sense of smell makes an ovulating woman more sensitive to the lure of her partner's pheromones, those scent-producing chemical compounds that nature releases to put the sex drive into overdrive. The result? You're in the mood for lovin' just when nature (and you) wants you to be (when lovin' is most likely to produce a baby). So take advantage of your ovary-stimulated inner beagle. If you're feeling like you could track a pheasant through the woods (or at least a garlic-roasted chicken), chances are this is a good time to hop in the sack and try to make a puppy…or, rather, a baby.

Body temperature

 Your basal body temperature (BBT) is lower when your body is heading toward ovulation but rises about a degree when you ovulate. That’s because the hormone estrogen, which lowers your BBT, dominates the first half of your cycle, while progesterone, which raises your BBT, surges once you ovulate (to get the uterus ready to receive the fertilized egg). So this week you’ll see a rise in your BBT if you’ve been keeping track.

Clear cervical mucus with an egg-white consistency

 Last week your mucus was getting thinner and looking a little cloudy; this week it’s extra-thin, extra-stretchy, and clear (or whitish) — perfect traveling conditions for sperm heading upstate (toward the egg).

Possible lower-abdominal achiness (mittelschmerz)

 About one in four women feel a twinge or series of cramps in the lower abdominal area — usually one side (the side they’re ovulating from). This pain, which is thought to come from an ovary releasing an egg, is known as mittelschmerz (from the German word meaning “middle pain”).

Tip of the Week

Get yourself a good doctor...pronto! Having a healthcare provider you like and trust is key. After all, this is the person who will guide you through your entire pregnancy, labor, and delivery, along with the millions of questions, tests, and emotional ups and downs along the way.