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Pregnancy: Week 4
Symptoms experienced during this week can be very similar to those experienced shortly before a typical period. These symptoms include breast tenderness, headaches, lower backaches, and nausea. Your embryo is less than 2 millimeters in size. The placenta is starting to form.
At four weeks, you are finally far enough along to take a pregnancy test, and for that test to show up as positive. If the test is negative, and you still suspect that you are pregnant, wait one week before taking another test.
External Links
- American Preganancy Association: 4 Weeks Pregnant (https://americanpregnancy.org/healthy-pregnancy/week-by-week/4-weeks-pregnant/)
- Baby Center: Kate Marple & Layan Alrahmani, M.D., ob-gyn, MFM: 05/30/2025: 4 weeks pregnant (https://www.babycenter.com/pregnancy/week-by-week/4-weeks-pregnant)
- Healthline: Debra Rose Wilson, Ph.D., MSN, R.N., IBCLC, AHN-BC, CHT & Ashley Marcin: 10/19/2017: 4 Weeks Pregnant: Symptoms, Tips, and More (https://www.healthline.com/health/pregnancy/pregnancy-week-4)
- NHS: Week 4 (https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/1st-trimester/week-4/)
- The Bump: Lauren Barth & Kendra Segura, MD & Shannon Simcox: 05/21/2025: 4 Weeks Pregnant (https://www.thebump.com/pregnancy-week-by-week/4-weeks-pregnant)
- What To Expect: Catherine Donaldson-Evans & Jennifer Wu, M.D., F.A.C.O.G.: 07/29/2025: 4 Weeks Pregnant: Your baby is as big as a poppy seed. (https://www.whattoexpect.com/pregnancy/week-by-week/week-4.aspx)