The short answer
37 weeks = 9 months
At 37 weeks pregnant, you are about 9 months pregnant — in month 9 of your pregnancy and in your third trimester.
Not sure of your week? Use the pregnancy week calculator to find it from your last period, due date or conception date.
Early term begins. The lungs are close to fully ready, and labor could realistically start any week now.
About the size of a bunch of Swiss chard
size comparison
48.6 cm
crown to heel (19.1 in)
2.9 kg
average weight (6.4 lb)
The fetus practices sucking a thumb, grasping and turning toward light — coordination it will need for feeding within hours of birth. Fat is being laid down at about half an ounce a day, and the head circumference is roughly equal to the chest. Hair length varies enormously; some babies are born with a full head of it and some with almost none.
Sizes and weights are averages — healthy babies vary widely, and your scan measurements are what count.
Increased vaginal discharge is typical, and some people pass the mucus plug (a thick, sometimes blood-tinged discharge) days or weeks before labor. A sudden burst of energy or urge to organize is common. Pelvic pain when rolling over in bed is a frequent complaint.
Common symptoms this week
21
days to go
3
weeks to go
259
days so far
At 37 weeks 0 days you are 259 days into a 280-day pregnancy, which leaves 21 days — 3 weeks — until 40 weeks. That number drops by one for every day you move through this week. Remember the due date is an estimate: only about 1 in 20 babies is born on it, and most arrive within two weeks on either side.
Next milestone: 14 days until full term (39 weeks 0 days).
Week 37 begins early term. It is no longer preterm, but full term does not start until 39 weeks 0 days — those last two weeks still add meaningful lung and brain maturity.
The term labels are set by exact week and day, not by month: early term is 37 weeks 0 days to 38 weeks 6 days, full term is 39 weeks 0 days to 40 weeks 6 days, late term is 41 weeks 0 days to 41 weeks 6 days, and post-term is 42 weeks 0 days onward. All four fall inside "9 months pregnant", which is exactly why your care team never uses months for this.
A calendar month averages about 4.3 weeks — not 4 — so you can't just divide your week number by four. Instead, months of pregnancy are counted as uneven buckets of 4 to 5 weeks, arranged so the full 40 weeks fits into 9 calendar months. Week 37 falls in month 9, in the third trimester.
Your care team will always use weeks and days rather than months, because screening windows and term definitions are set by exact week — months are just the everyday shorthand. For the full conversion, see the weeks to months chart, or go the other way with the months-to-weeks guide.
Your notes will show a week and a day — 37+3 or 37w3d, for example. Pick the exact day you are on for its own day count, countdown and month answer.
| Week + day | Shorthand | Days pregnant | Days to go |
|---|---|---|---|
| 37 weeks 0 days (this page) | 37+0 | 259 | 21 |
| 37 weeks 1 day | 37+1 | 260 | 20 |
| 37 weeks 2 days | 37+2 | 261 | 19 |
| 37 weeks 3 days | 37+3 | 262 | 18 |
| 37 weeks 4 days | 37+4 | 263 | 17 |
| 37 weeks 5 days | 37+5 | 264 | 16 |
| 37 weeks 6 days | 37+6 | 265 | 15 |
At 37 weeks pregnant, you are about 9 months pregnant — in month 9 of your pregnancy and in your third trimester. Months of pregnancy are counted as uneven 4–5 week buckets so that the full 40 weeks fits into 9 calendar months.
37 weeks is in the third trimester, which runs from 28 weeks 0 days until birth. Full term begins at 39 weeks 0 days.
About 3 weeks until the 40-week mark — though only about 1 in 20 babies arrives exactly on the due date. Most are born within two weeks on either side of it.
At 37 weeks 0 days you are 259 days into a 280-day pregnancy, so there are 21 days left until the 40-week mark — that's 3 weeks. The count drops by one for each day you move through week 37.
37 weeks is 259 days, counted from the first day of your last menstrual period (37 × 7 = 259). Add the days into your current week for the exact figure — for example 37 weeks 3 days is 262 days.