First trimester · 34 weeks to go
| Fact | Week 6 |
|---|---|
| Days of pregnancy | 36–42 since LMP |
| Gestational age span | 5w0d to 5w6d |
| Trimester | First trimester (weeks 1–13) |
| Pregnancy month | Month 1 (weeks 1–4) |
| Average length | 0.13 in (crown to rump) |
| Average weight | not yet measurable |
| Size comparison | a lentil |
| Weeks remaining | 34 (40-week due date) |
Week 6 often brings the first ultrasound glimpse: a flickering heartbeat around 110 beats per minute. Meanwhile nausea tends to arrive in force, because hCG is climbing fast and the embryo's heart now has visible chambers forming.
The heart is dividing into chambers and beating at roughly twice your resting rate. Arm and leg buds poke out, the neural tube along the back is closing, and dark spots mark the earliest eyes. The tail-like structure is at its most prominent this week.
Gestationally, week 6 means you are 5 weeks and 0 to 6 days pregnant, day 36 to day 42 counted from the first day of your last period. This is week 6 of the first trimester (weeks 1–13). Prenatal appointments run about every four weeks in this stretch. Week 10 brings graduation from embryo to fetus. If your cycle runs longer or shorter than the 28 days the due-date math assumes, your ovulation date and due date shift with it, which is why a first-trimester ultrasound remains the gold standard for dating. Every number on this page is an average across pregnancies; your own scan dates and your baby's measurements are what actually describe your week 6.
Eat small amounts every couple of hours; an empty stomach makes nausea worse. Call your provider about any bleeding that fills a pad, but mild cramping is common.
Weeks of pregnancy don't map cleanly to calendar months, but the common division puts week 6 falls in month 1 of pregnancy (weeks 1–4). Week 6 is part of the first trimester, which runs from week 1 to week 13. Gestationally, week 6 means you are 5 weeks and 0 to 6 days pregnant.
At week 6 there isn't much to measure yet; the baby is on the scale of a lentil. Measurable length in inches begins with the embryo stage in the next few weeks.