periods.day
Could I be pregnant?
Start with your last period
Look back at your estimated fertile days and understand your next steps. A calendar cannot confirm or rule out pregnancy.
Enter your bleeding days, not the date of sex. Then explore that date on the calendar.
Period days logged
0 days
Estimated cycle length
28 days
Typical period length
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Log days you bled. Hover or hold the date of sex to explore its estimate.
01
Mark each day of your last period. Earlier periods help personalize the model, but cannot make it certain.
02
Navigate to that month, then hover or hold the date for an estimated phase. The cycle summary shows today.
03
Test from the first day of a missed period. If you do not know when it is due, test at least 21 days after the most recent unprotected sex.
periods.day has no accounts, cookies, analytics, or saved cycle data. Your entries live only in the link.
Anyone with the full link can see your entries. Share the link only with people you trust.
I was tired of having something as simple as tracking my cycle used to target me with ads for period underwear, fast food, or makeup. I wanted to understand my body and what it needs without advertisers exploiting that information. That’s why I built this site.
No. The calendar estimates timing from period dates. It does not know when you actually ovulated, whether fertilization occurred, or whether you are pregnant. Use a pregnancy test at the appropriate time.
Yes. Ovulation can shift, even with regular cycles, and sperm can survive for several days. A predicted lower-fertility day does not rule out pregnancy.
From the first day of a missed period, or at least 21 days after the most recent unprotected sex if you do not know when your period is due. An early negative result may need repeating. Seek medical advice if your period remains absent.