Morning-after pill
and your period
By Ben Jonas Goedeke · 2 min read · checked against its sources
Emergency contraception works mainly by delaying ovulation. That is why it can change when your next period arrives.
After taking it, your period may come a few days early or a few days late, and it may be lighter or heavier than usual. For most people it arrives within about a week of when it was expected.
What Tideline does with it
If you log the morning-after pill, Tideline widens its estimate for that cycle. An app that carries on as if nothing happened will give you a confident date that is probably wrong.
When to check
If your period is more than a week late, or unusually light, take a pregnancy test. If you have severe pain low in your belly, see a doctor promptly.
Keep the record your doctor needs. Tideline is a period and mood tracker for iPhone: write one sentence a day, and after two cycles it puts the week before your period next to the week after it starts. Free to track, no account.
Get Tideline on the App Store