Read more: FAQs & context
Boundary definitions
We use common week boundaries (end of 13 and 27 completed weeks). Some regions label trimesters slightly differently—ask locally.
Trimesters
First trimester through week 13 day 6; second through 27 day 6; third from week 28 onward (common convention).
Purpose, how to use it, and benefits — the interactive tool is in the card above whenever you want to jump back.
Shows which trimester you are in today and how many days remain until the end of that trimester or until your 280-day EDD in the third trimester.
Enter LMP and tap Show trimester countdown. Use Copy to paste milestones into your calendar app.
Screening tests, energy levels, and fetal size discussions are often organised by trimester in apps and classes.
We use common week boundaries (end of 13 and 27 completed weeks). Some regions label trimesters slightly differently—ask locally.