The pregnancy first trimester timeline shows week-by-week fetal development, baby size comparisons, and maternal changes for weeks 1-13. Enter your last menstrual period (LMP) date to see dates alongside each milestone.
If you don't know your LMP, the timeline still shows all milestone descriptions without specific dates.
Estimated Due Date
Based on 40 weeks from LMP
How to Navigate the First Trimester
The first trimester is a period of extraordinary development — your baby goes from a cluster of cells to a recognizable human form in just 13 weeks. It is also typically the most challenging period for expectant parents, with morning sickness, fatigue, and anxiety about the pregnancy's progress.
Start prenatal care immediately
Begin prenatal vitamins with folic acid (400-800mcg) before week 6 if possible — folate is critical in the first weeks before most women know they're pregnant. Schedule your first prenatal appointment early to establish care and confirm the pregnancy location (ruling out ectopic pregnancy) and viability.
Managing first trimester symptoms
For morning sickness: small, frequent meals help more than large ones. Bland carbohydrates (crackers, plain toast) often work when nothing else appeals. Cold foods have less aroma than hot foods. Ginger (tea, candies, supplements) has evidence for nausea reduction. For severe nausea/vomiting (hyperemesis gravidarum), see your provider — safe anti-nausea medications are available.
First trimester screening tests
First trimester screening combines nuchal translucency ultrasound (weeks 11-14) with blood tests (PAPP-A and hCG) to screen for chromosomal conditions like Down syndrome. Cell-free DNA (NIPT) testing is also available from week 10. These are screening tests — a positive result leads to confirmatory diagnostic testing.
Every pregnancy is unique. Consult your healthcare provider for personalized guidance.
FAQ
Is this pregnancy timeline tool free?
Yes, completely free with no signup required.
Is my data private?
Yes. No data is sent to any server. Your LMP date stays in your browser.
When does the first trimester end?
The first trimester ends at the end of week 13 (day 91 of pregnancy). The second trimester runs weeks 14-27, and the third trimester from week 28 until birth. The risk of miscarriage drops significantly after week 12 — most couples choose to share their news after this milestone.
When should I schedule my first prenatal appointment?
Schedule your first prenatal appointment as soon as you get a positive pregnancy test — typically around 6-8 weeks. The appointment is usually at 8-10 weeks, which includes a confirmation ultrasound, medical history review, blood tests, and urine testing. Don't wait until after the first trimester to begin prenatal care.
When does morning sickness typically start and end?
Morning sickness typically begins around week 6, peaks at weeks 8-10, and improves significantly by week 12-14 for most women. The misleading name 'morning sickness' belies that it can occur at any time of day. About 70-80% of pregnant women experience nausea, and about 50% experience vomiting in the first trimester.