Find out exactly how many weeks and days pregnant you are today, your current trimester, percentage of pregnancy complete, and what's happening with your baby right now — plus upcoming milestones.
How Far Along Are You?
Gestational Age—
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Due Date—
Days Until Due Date—
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What's Happening This Week
Upcoming Milestones
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Full Timeline: Weeks 1–40
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Date
Trimester
Key Development
How Gestational Age Is Counted
Doctors count pregnancy from the first day of your last menstrual period (LMP). This means at conception (around week 2), you're already "2 weeks pregnant" by gestational count. The 40-week total includes approximately 2 weeks before conception occurred.
This standard is universal in obstetrics, which is why ultrasound reports, clinical guidelines, and all pregnancy apps use gestational age from LMP.
Term Definitions (ACOG)
Early preterm: less than 34 weeks
Late preterm: 34–36 weeks
Early-term: 37–38 weeks
Full-term: 39–40 weeks (optimal for delivery)
Late-term: 41 weeks
Post-term: 42+ weeks
How Pregnancy Weeks Are Counted
Pregnancy is counted from the first day of the last menstrual period (LMP), not from conception. This means the clock starts about two weeks before fertilization, which is why a full-term pregnancy is 40 weeks from LMP even though conception happens around week 2.
Gestational age is divided into three trimesters: weeks 1–12 (first), 13–26 (second), and 27–40 (third). Each has distinct developmental milestones and corresponding prenatal care visits. Key screenings are timed to specific gestational weeks: first-trimester screening (10–13 weeks), anatomy scan (18–20 weeks), glucose challenge test (24–28 weeks), and Group B strep test (35–36 weeks).
Worked Example
If your last period started on January 1, 2025, and today is May 5, 2025: days since LMP = 124 days. Weeks pregnant = 124 ÷ 7 = 17 weeks and 5 days. You are in the second trimester (weeks 13–26). Your due date is October 8, 2025 (280 days after January 1). You are 44% through your pregnancy with 156 days remaining. The anatomy scan should be scheduled for approximately May 21 (week 20). You would start kick counting around week 28, which falls on July 23.
Frequently Asked Questions
Full term is 39–40 weeks from LMP. Early term is 37–38 weeks; late term is 41 weeks; post-term is 42+. Most providers recommend induction or close monitoring after 41 weeks due to increased risk of complications. Babies born at 39–40 weeks have the best outcomes for lung maturity, feeding, and neurodevelopment compared to earlier or later delivery.
If your LMP is unknown, your provider can estimate gestational age from an early ultrasound. Crown-rump length (CRL) measured at 8–12 weeks is the most accurate dating method when LMP is uncertain. After 14 weeks, ultrasound measurements become less reliable for precise dating, so early scanning is important when LMP is unknown or irregular cycles make LMP-based dating unreliable.
In the first trimester, major organs form and the embryo becomes a fetus. The second trimester includes the anatomy scan at 18–20 weeks, and most parents find out the baby's sex. The third trimester involves rapid weight gain, lung maturation, and preparation for birth. Movement is typically felt around 18–22 weeks in a first pregnancy, and earlier in subsequent pregnancies.
First trimester (weeks 10–13): combined screening for chromosomal abnormalities (nuchal translucency ultrasound + blood test for hCG and PAPP-A). Weeks 14–20: optional amniocentesis or CVS for diagnostic testing. Week 18–20: anatomy ultrasound checks all fetal organs. Week 24–28: glucose challenge test for gestational diabetes. Week 28: Rh factor check; RhoGAM injection if needed. Week 35–36: Group B streptococcus swab test.