How Many Weeks Pregnant Am I?

Enter your last period date to find out exactly how far along you are, what's happening with baby this week, and what milestones are coming up.

These weeks are calculated from your LMP. If your OB-GYN or midwife has set a different date by ultrasound, use that one — ultrasound dating is more accurate, especially with irregular cycles.

What to track each pregnancy week

Knowing your week is the orientation point. The data that actually shapes how your pregnancy unfolds — and what your provider will ask about at every visit — is what you log between appointments.

Symptoms by trimester

The first trimester is mostly about nausea, fatigue, food aversions, and breast changes. Log time of day, severity, and what helps. The second trimester is when first movements arrive (weeks 18-22 typically), along with round-ligament pain, skin changes, and a usually-welcome energy rebound. The third trimester shifts to baby movement counts, Braxton Hicks, swelling, sleep changes, and prep for labor.

Baby movements (after week 28)

Kick counts are one of the few things you can do at home that has real clinical value. After 28 weeks, most providers recommend tracking 10 movements within 2 hours once a day. A sudden decrease in normal movement is the most important thing to log and call about — written counts make that call much easier.

Weight, blood pressure, mood, and sleep

Weekly weight gain is more useful than monthly — the curve matters more than the number. Home blood pressure is worth logging if your provider flagged it (preeclampsia signal). Mood and sleep are the most overlooked: prenatal depression affects ~1 in 7 women and is best caught early, and sleep often deteriorates well before the third trimester.

What ongoing tracking actually unlocks

A calculator gives you "weeks + days." A tracking app gives you week-by-week comparison: how this week's symptoms compare to last, when something shifts, and a written record to bring to every prenatal appointment. See our pregnancy tracking guide for the trimester-by-trimester checklist, or pregnancy wellness tips for what to focus on week by week.

Up next: Need your estimated delivery date? Try the due date calculator. Planning for after baby arrives — or for a future pregnancy? The ovulation calculator and period calculator are useful once cycles resume postpartum.

Knowing your week is just the start.

Gaia tracks your symptoms, mood, sleep, and weight alongside baby's development — and helps you spot what to flag at every prenatal visit. So the data your provider sees is yours, not an average from a textbook.

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Common Questions About Pregnancy Weeks

Your pregnancy is counted from the first day of your last menstrual period (LMP) — not from conception. So when your period is a week late, you're technically already about 5 weeks pregnant. Enter your LMP date into the calculator above to get your exact week and day count, plus your trimester and due date.

Pregnancy is dated from the first day of your last period because that's a date most people can pinpoint — ovulation and conception dates are harder to know for sure. From your LMP, your doctor counts forward 280 days (40 weeks) to estimate your due date. The first two weeks of your "pregnancy" are actually before ovulation even happens, which feels weird but it's how the math works.

The first trimester covers weeks 1 through 12 — this is when morning sickness, exhaustion, and sore breasts tend to peak. The second trimester runs from week 13 to 26, and most people feel their best during this stretch (hello, energy boost). The third trimester is weeks 27 through 40, when baby is packing on weight and you're getting ready for delivery.

Baby's size changes fast! At 8 weeks, they're about the size of a raspberry. By 20 weeks — the halfway point — they're banana-sized. And by 40 weeks, you're looking at a small pumpkin (around 51 cm and 3.5 kg). Use the calculator above to see your baby's current size comparison, length, and weight for your exact week.

Gestational age counts from the first day of your last period — this is the number your doctor uses and what you'll see on ultrasound reports. Fetal age (also called embryonic age) counts from the actual date of conception, which is roughly 2 weeks less. So if you're 10 weeks pregnant by gestational age, your baby has really only been developing for about 8 weeks. Most pregnancy apps and calculators use gestational age.

Technically, no — once you're pregnant, you don't get a true period. But some people do experience light bleeding or spotting in early pregnancy, which can look a lot like a period. This is sometimes implantation bleeding (around 6-12 days after conception) or breakthrough bleeding. If you're pregnant and bleeding, it's worth mentioning to your provider just to rule out anything that needs attention.

Educational content, not medical advice. Pregnancy week counts here are estimates from your LMP. Follow your OB-GYN or midwife's guidance — they have your ultrasound dates, history, and clinical context. Contact your provider right away for heavy bleeding, severe pain, persistent vomiting, or reduced fetal movement after week 28. Go Go Gaia is a tracking tool, not a substitute for prenatal care.