First trimester · 31 weeks to go
| Fact | Week 9 |
|---|---|
| Days of pregnancy | 57–63 since LMP |
| Gestational age span | 8w0d to 8w6d |
| Trimester | First trimester (weeks 1–13) |
| Pregnancy month | Month 1 (weeks 1–4) |
| Average length | 0.9 in (crown to rump) |
| Average weight | not yet measurable |
| Size comparison | a green olive |
| Weeks remaining | 31 (40-week due date) |
Week 9 is graduation season: the basic body plan is complete, and from here it's growth and refinement. All four heart chambers have formed, the tail is gone, and sex organs begin differentiating, though ultrasound can't tell yet.
The embryo looks distinctly human in miniature. Tooth buds form, and fine details like separated fingers emerge. The liver is producing red blood cells, and the placenta is preparing to take over hormone production.
Gestationally, week 9 means you are 8 weeks and 0 to 6 days pregnant, day 57 to day 63 counted from the first day of your last period. This is week 9 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 9.
Small, frequent meals beat three large ones for heartburn. Note your emotional dips are hormonal chemistry, not character; they're expected this trimester.
Weeks of pregnancy don't map cleanly to calendar months, but the common division puts week 9 falls in month 1 of pregnancy (weeks 1–4). Week 9 is part of the first trimester, which runs from week 1 to week 13. Gestationally, week 9 means you are 8 weeks and 0 to 6 days pregnant.
At week 9 there isn't much to measure yet; the baby is on the scale of a green olive. Measurable length in inches begins with the embryo stage in the next few weeks.