Week 3 of Your Pregnancy

Verywell / Bailey Mariner

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Conception! Even though the start of your pregnancy journey began two weeks ago at week 1, the start of your baby’s development begins this week. While you won’t know if you’re officially pregnant until the end of week 4 or in week 5, during week 3, a new little life is beginning to take form.

Which Trimester? First trimester

How Many Weeks to Go? 37 weeks

Your Baby's Development at 3 Weeks

Fertilization, or the joining of the egg and sperm, is the first step in your child’s development. This week the fertilized egg grows from a one-cell zygote into a ball of cells called a blastocyst.

From zygote to blastocyst, your tiny baby measures 0.1 mm–0.2 mm (100–200 microns), or about the size of the head of a pin.

At 3 weeks pregnant, your baby is about the size of a cloth diaper pin
Verywell / Bailey Mariner 

Growing and Dividing

After fertilization, the egg is called a zygote. The zygote begins to divide from one cell to two, then two to four, and then four to eight, and so on. As it does, it travels through the fallopian tube to the uterus—a journey that takes three to five days. Once in the uterus, and about five days after fertilization, the ball of cells becomes a blastocyst.

What About Twins?

During week 3 development, one baby can become two. Identical twins come from the same egg and sperm with the same genetic material. The fertilized egg can split into two identical groups of cells at different stages, such as the two-cell stage or the blastocyst stage. But, it usually happens during the first week after conception.

Fraternal twins are another possibility this week. Fraternal twins do not come from the same egg and sperm. It takes two eggs and two sperm to have fraternal twins. So, if you release two eggs during ovulation and each egg is fertilized by different sperm, then you’ll have two separate zygotes or fraternal twins.

Stay Calm Mom: Episode 1

Watch all episodes of our Stay Calm Mom video series and follow along as our host Tiffany Small talks to a diverse group of women and top doctors to get real answers to the biggest pregnancy questions.


Am I Pregnant? Real Women Share Their Early Signs

Your Common Symptoms This Week

Even though a lot is going on in your body right now, it isn’t anything you can truly feel. During week 3, you can’t tell that you’re pregnant yet, and you don’t necessarily have any physical symptoms.


You may, however, be experiencing some emotional symptoms. As you think about the beginning of this new journey, it may fill you with excitement. Or, you may feel nervous and anxious as you wait to take a pregnancy test.

Of course, you can go back and forth between emotions or even experience them all at the same time. It is all very normal. Pregnancy can be an emotional roller coaster, even this early.


When your tiny baby reaches your uterus, it will find a spot to attach or implant into the uterine wall. As it burrows in, it sometimes causes a small amount of bleeding or spotting.

If you do not see any spotting around the time of implantation, it doesn’t mean you aren’t pregnant. Not everyone will have this symptom.

What Experts Say

“The blood is a natural byproduct of the embryo burrowing into the uterine wall and delicate, new blood vessels breaking apart.”
Allison Hill, MD, OB/GYN

Implantation and implantation spotting are more likely to take place next week, during week 4. However, it can happen as early as six days after ovulation, so at the very end of week 3.

Self-Care Tips

Weeks 3 and 4 of pregnancy are a bit of a waiting game. Continue to care for yourself by trying to eat well, getting in some activity, and staying positive.

Work on Your Diet

Start or continue to add healthy foods to your daily diet to get all the nutrients you need to nourish your body and a growing baby—especially iron and folate.

Keep Taking Those Vitamins

It’s not always easy to get all the nutrition you need through your diet, so start or continue to take prenatal vitamins. Vitamins aren’t a substitution for healthy eating, but they do help fill in the gaps.

Get a Little Exercise

Staying active can help you maintain a healthy weight, give you energy, boost your mood, and reduce stress. The American College of Obstetricians and Gynecologists (ACOG) recommends 150 minutes of physical activity per week.

But don’t overdo it. And, don’t forget to talk to your doctor before starting an exercise program if you have any health concerns.

Use Positive Affirmations

As you prepare physically for pregnancy, you can also prepare mentally. Positive affirmations are thoughts and phrases that you repeat to yourself. They can help you overcome any fear or anxiety you have as you wait for a pregnancy test.

Try saying something like, “My body is ready and capable of nourishing a baby.” It certainly doesn’t hurt to think positively.

Your Week 3 Checklist

Advice for Partners

Now is a good time for partners to encourage healthier lifestyle choices by participating in them. Go grocery shopping together to pick out some healthy meal choices and cook them together. Get some fresh air, go for a walk, and spend time engaging in physical activities you both enjoy. 

Stay away from alcohol and other harmful substances together. It’s easier to make good choices and stick with the changes when you support and encourage each other.  

Upcoming Doctor's Visits

You may visit a doctor’s office or lab for a blood test to confirm a positive home pregnancy test during week 5. Your doctor may schedule your first prenatal visit between week 6 and week 8.

Recommended Products

You might be looking for information this week as you wait to find out the news. Take a look at some pregnancy books and consider purchasing a home pregnancy test to have on hand when it’s time to test. 

Pregnancy Tests

It’s too early to take a home pregnancy test in week 3. But, by the middle or later part of next week, you might be able to detect the pregnancy hormone hCG in your urine with a sensitive early test. 

Pregnancy Books

Pregnancy books can provide information, tips, answers to questions, and even a little humor. Some books are a great resource to help ease your mind, and others are fun and relatable when you need a good laugh.

Special Considerations

Week 3 puts you between ovulation and taking a pregnancy test. That leaves you with a little time on your hands. The wait might be easy or a little stressful.

Try to resist the temptation to take an early test. Instead, stay busy by researching healthcare providers, getting together with friends, or doing things you enjoy. 

Choosing a Healthcare Provider

Again, there’s no need to schedule a prenatal appointment just yet. However, if you haven’t decided on a doctor or a midwife, you can use 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 a few practitioners. Tell them you’re in the market for a new provider and that you’d like to have an initial meeting to get to know them and ask questions.

What Experts Say

“Don’t be afraid to hold your OB/GYN or midwife to a high standard. 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.”

Allison Hill, MD, OB/GYN 

The 2-Week Wait

The two-week wait between ovulation and taking a pregnancy test can be exciting, but hard. If you’ve been trying to conceive for a while or you’re undergoing fertility treatments, the two-week wait can feel like an eternity.

You might obsess and analyze every twinge and tingle looking for any sign of pregnancy. You might spend a lot of time worrying about all the “what-ifs.” Excitement, anxiety, and worry are all normal emotions, but it’s important to try to manage them.

Keep busy and find ways to distract yourself when the worries return. Talk about your feelings with your partner, then do something fun together. Or, reach out to your friends or an online group to help you get through the long days of waiting.

Taking a Pregnancy Test

Pregnancy tests detect human chorionic gonadotropin (hCG). This pregnancy hormone rises quickly in your body after implantation, but during week 3, it is too early to detect hCG. Even the most sensitive tests will not pick up the pregnancy hormone until sometime next week. 

What Experts Say

“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.”

Shara Marrero Brofman, PsyD

Testing too early is unreliable as it can lead to a false result. If it’s negative, it doesn’t mean that you aren’t pregnant—it could just be too early to tell. You can avoid that disappointment if you wait a little longer. 

If you are undergoing fertility treatments, testing too early can result in a false positive. The test can pick up hCG leftover from your trigger shot. It doesn’t mean you are pregnant, and it doesn’t mean you aren’t. It means you have to test again later when the time is right.

It can be tough to wait, but the best time to take a pregnancy test is after you miss your period.

A Word From Verywell

Week 3 brings the amazing dawn of new life. You can’t feel it or see it yet, but it’s making its way to your uterus, where it will find the perfect spot to call home for the next 37 weeks.

Implantation may take place at the very end of this week, but it’s more likely your tiny creation will attach and begin the next stage of growth next week. The end of week 4 also brings the possibility of a positive early home pregnancy test.

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Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Holly Pevzner
Holly Pevzner is an award-winning writer who specializes in health, nutrition, parenting, and family travel.