Highlights this week
The two-week wait
If you're ready to be pregnant, the next weeks may feel like the longest of your life. You're in the so-called two-week wait (TWW), the interval between when you may have conceived and when you can get a positive pregnancy test. Home pregnancy tests are only accurate on (or after) the first day of your missed period, so hold off on taking one just yet.
Implantation
Implantation
Your developing blastocyst has travelled down your fallopian tube to your uterus – and by the end of the week or the beginning of next, it may implant itself in the lush uterine lining. (Before it implants, the blastocyst sheds its clear outer shell in a process called "hatching"!) You probably won't be aware all this is happening, though some women experience mild implantation bleeding or implantation cramping.
Early pregnancy symptoms
Most women don't feel anything until they've missed a period, but you may notice bloating, cramping, or spotting this week. Your breasts may also be more tender than usual and you may have a heightened sense of smell, one of the earliest pregnancy symptoms. So if your partner, your house, or your dog suddenly smells different to you, thank your surging hormones.
Baby development at 3 weeks
- The fertilized egg is moving down the fallopian tube to the uterus
- Called a blastocyst, your baby-to-be is now a rapidly dividing ball of cells
BabyCenter Zodiac
What will your baby's zodiac sign be? See what it says about their personality.Find your baby's zodiac
Uncover your nesting personality
Whether you're deep into decor or organizing everything, let’s decode your nesting vibe.Take the quiz
Find your pregnancy energy level
Powering through or powering down? No judgment, just vibes.Take the quiz
Discover your pregnancy style
Every mama’s journey is different — and so is her vibe! Discover your pregnancy persona.Take the quiz
Your body at 3 weeks pregnant
- Your baby-to-be is burrowing into the lush lining of your uterus
Early pregnancy hormones
The cells that will become the placenta are pumping out the pregnancy hormone hCG. It tells your ovaries to stop releasing eggs and keep producing progesterone, which prevents your uterus from shedding its lining – and its tiny passenger. Once there's enough hCG in your urine, you'll get a positive pregnancy test result.
Amniotic fluid
Amniotic fluid is beginning to collect within the amniotic sac. This fluid will cushion your baby in the weeks and months ahead, and it's what may eventually come gushing out of you if your water breaks before or during labor.
Pregnancy symptoms during week 3
Track every pregnancy symptom – big or small – with the Symptom Tracker tool in the BabyCenter app. It’s the easiest way to stay in tune with your body and bring helpful notes to your next appointment. Here’s what you might notice during week 3.
Some women feel pregnant even before the test is positive, but most don't. If you have pregnancy symptoms this week, they may feel like PMS. But don't worry if you haven't felt anything different yet. Even at 5 weeks pregnant, only half of women feel pregnancy symptoms.
Some women say their sore breasts in early pregnancy are like an exaggerated version of how they feel before a period. Your breasts may feel swollen, tender, or tingly – and your nipples may be extra sensitive and uncomfortable. Later in pregnancy, you may notice your nipples getting darker.
You may have a bit of light bleeding (spotting) this week. This is implantation bleeding – it can happen around the time the fertilized egg implants in your uterus. It's a lot lighter than a typical period, and only lasts for one to three days. (If you have pain along with bleeding, call your healthcare provider immediately. This can be a sign of an ectopic pregnancy.)
If you're charting your temperature, it should stay elevated this week. To keep track, use a basal body thermometer and take your temperature after you wake up in the morning, before you get out of bed.
Pregnancy checklist at 3 weeks pregnant
Pay attention to your emotions
When you're waiting to learn whether you're pregnant or not, or just finding out, it's normal to be anxious. If you're feeling stressed or worried, talk to your partner or a trusted friend. Or, try writing down everything that's bothering you. Journaling can improve your emotional well-being, mental clarity, and even physical health.
Avoid overheating
Hot baths are okay during pregnancy as long as they aren't too hot. But avoid steam baths, hot tubs, and saunas. Elevated body temperature, especially early in pregnancy, has been associated with an increased risk of neural tube defects in babies.
Eat nutritious meals and snacks
Eat pregnancy-friendly foods such as fruits and vegetables, low-mercury fish, and whole grains. Choose foods containing vitamin C (like strawberries, citrus fruits, bell peppers, and tomatoes), iron (like beef, poultry, soy products, and spinach), and calcium (like Greek yogurt, fortified cereal, and pasteurized cheese). For snack ideas, check out 10 of our favorite healthy snacks for expecting moms.
Cut down on coffee
While you're trying to conceive and once you get pregnant, experts recommend limiting caffeine to about one cup of coffee a day. It's important to watch your caffeine intake because having too much can affect your pregnancy and your baby. See how much caffeine is in different foods and drinks so you can stay under the recommended daily limit.
Get help quitting
If you need help quitting smoking, drinking, or taking drugs, talk to your healthcare provider and ask for a referral to a program or counselor.
Improve your sleep
When pregnancy-related sleep problems hit in a few months, be ready for them. Create better habits around sleep and work on good sleep practices like establishing a regular bedtime routine and making your bedroom a sleep sanctuary.
Make sure your work and home are safe
Some jobs can be hazardous to you and your baby. If you're routinely exposed to chemicals, loud noises, or radiation at work, or if you have to be on your feet constantly or lift heavy objects, talk to your provider about how to stay safe while working during pregnancy. Also, keep in mind that some things in your home may be dangerous for your developing baby. Lead (in drinking water from old pipes), mercury (in certain fish), certain pesticides and fertilizers, and cat litter containing feces are all potentially harmful.
BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organizations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.
ACOG. 2024. How your fetus grows during pregnancy. American College of Obstetricians and Gynecologists. https://www.acog.org/womens-health/faqs/how-your-fetus-grows-during-pregnancyOpens a new window [Accessed August 2024]
Cleveland Clinic. 2022. Blastocyst. https://my.clevelandclinic.org/health/body/22889-blastocyst Opens a new window[Accessed August 2024]
FDA. 2019. Home use tests: Pregnancy. U.S. Food and Drug Administration. https://www.fda.gov/medical-devices/home-use-tests/pregnancyOpens a new window [Accessed August 2024]
Mayo Clinic. 2022. Fetal development: The 1st trimester. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302Opens a new window [Accessed August 2024]
Mayo Clinic. 2024. Symptoms of pregnancy: What happens first. https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/symptoms-of-pregnancy/art-20043853Opens a new window [Accessed August 2024]
MedlinePlus (ADAM). 2023. Fetal development. https://medlineplus.gov/ency/article/002398.htmOpens a new window [Accessed August 2024]
NIH. 2017. What are some common signs of pregnancy? National Institute of Child Health and Human Development, National Institutes of Health. https://www.nichd.nih.gov/health/topics/pregnancy/conditioninfo/signsOpens a new window [Accessed August 2024]
