Week 3 of Your Pregnancy

A look at your body, your baby, and more

Welcome to week 3 of your pregnancy. You’ve got a tiny—but rapidly dividing—zygote (or a fertilized egg) steadily moving through your fallopian tube, working to find a place in your uterus to eventually burrow in and call home. It’ll take about three to five days to complete this journey, but even when finished, you’re likely to still get a negative pregnancy test result.

week 3 pregnancy highlights
Illustration by Verywell

Your Trimester: First trimester

Weeks to Go: 37

You This Week

You may experience some light vaginal spotting, called implantation bleeding, this week. While many mistake this for lighter-than-normal menstrual flow, it’s actually considered the first sign of pregnancy. “The blood is a natural byproduct of the embryo burrowing into the uterine wall and delicate, new blood vessels breaking apart,” explains Allison Hill, M.D., an OB-GYN and author of Your Pregnancy, Your Way and co-author of The Mommy Docs’ Ultimate Guide to Pregnancy and Birth.

If you misinterpret or never experience this clue, that’s normal, too. It seems that only 3 percent of women count implantation bleeding as their first indication of pregnancy, according to a survey from the American Pregnancy Association.

Your Baby This Week

The cells that make up your zygote are rapidly increasing and heading straight for your uterus; this takes about three to five days. Once in the uterus, the cells of the zygote continue to divide, morphing into a hollow clump of cells called a blastocyst.

Next, the blastocyst begins to burrow and attach to near the top of the uterine lining. This is called implantation. (The cells on the inside of the blastocyst become the embryo. Those on the outside become the yolk sack and the placenta, which will soon nourish your baby.)

While the stage has already been set if you’re carrying fraternal twins, this is when the possibility of identical twins comes into play. Identical twins, which are formed when one fertilized egg splits, can begin to form within the first 30 hours of fertilization up through and five to six days after it. No matter if you are carrying one or more babies, right now, your zygote is about .0019 inches big, which means it’s approximately the size of the head of a pin.

Taking Care

At the end of this week, your body begins to produce small amounts of the pregnancy hormone human chorionic gonadotropin (hCG), which can sometimes (but not always) lead to early pregnancy symptoms like tender, swollen breasts and fatigue. The thing is, there’s still likely not enough of the hormone present in your body to be detected by a pregnancy test yet. “Many patients test too early, get a negative result, and then get the false impression that they are not pregnant,” says Dr. Hill.

On the flip, an early positive pregnancy test may indicate a chemical pregnancy. This is when the pregnancy ends shortly after implantation. “While some women may want to know about this loss, many don’t,” says Shara Marrero Brofman, PsyD, a reproductive and perinatal psychologist at the Seleni Institute. This is why it’s generally best to wait until the day of your missed period to do the test. “It’s hard to wait. Uncertainty can be very anxiety-provoking, but there’s something to be said for accepting your lack of control. It can actually be a great relief,” says Dr. Brofman.

At Your Doctor’s Office

Again, there’s no need to schedule a doctor’s appointment as of yet. However, you can take this time to further scope out what sort of healthcare provider you’d like to see throughout your pregnancy. Ask local friends and family who’ve recently had a baby for their recommendations. Next, make some appointments with doctors and/or certified nurse-midwives, telling them that you are in the market for a new provider and you’d like to have an initial meeting to get to know them and ask some questions.

“Don’t be afraid to hold your OB-GYN or midwife to a high standard,” says Dr. Hill. And know this: The decision you make today doesn’t have to be your decision for the duration of your pregnancy. “Right now, you might not even know what’s important to you. As your pregnancy progresses and you learn more about your options, you may discover that the provider you selected does not fit your ideals any longer—and that’s OK,” says Dr. Hill. You absolutely can change your provider during pregnancy.

Upcoming Doctor’s Visits

In most cases, you can hold off scheduling your first prenatal visit until around eight weeks after your last menstrual period (LMP). However, if you’ve experienced recurrent pregnancy loss or even just anxiety about pregnancy, you can always ask your healthcare provider for an earlier appointment. “It’s important to know that not every practice will see you early,” says Dr. Brofman. “And this doesn’t necessarily indicate an insensitive doctor, just protocol of the office.”

Dr. Brofman’s advice: Find some healthy distraction and engage in some self-care.

For Partners

It’s hard for partners to wait, too. It’s natural for you both to be on edge. If the “what-if” talks about possible pregnancy are stressing you both out, it can be helpful to reserve those discussions for a specific time and place, notes Brofman. And in the meantime, take this time to distract yourselves together with some fun just-the-two-of-you activities.

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