🤰 Week by Week
Pregnancy Weeks: Pick Your Week
From week 4 to week 40, what develops in your baby, what changes in you and what to watch for — one page per week. Pick your week and start.
1st Trimester (weeks 4-13)
2nd Trimester (weeks 14-27)
3rd Trimester (weeks 28-40)
How Many Months Is Each Pregnancy Week? Conversion Table
Pregnancy months don't run in neat four-week blocks, so the week-to-month conversion rarely lands on a whole number — which is why pregnancy is tracked in weeks. The table below shows which month and trimester each week falls into.
Pregnancy Tracking
Follow your pregnancy week by week, track baby development, and log your health data. Prepare for birth with confidence.
Baby Development: Pick Your Month
From month 1 to month 12: the skills your baby gains each month, how much they sleep, how they feed and which vaccines are due.
Week-by-Week Pregnancy Guide: Weeks 4-40
Pregnancy week by week across three trimesters: your baby's growth from a lentil to a watermelon, the milestones from heartbeat to first kick, and what you experience in each period.