periods.day
Will my period overlap my trip?
Plan from your last period
Look ahead to a trip, festival or weekend away. Estimate when your period might arrive and pack with a little more peace of mind.
Add your recent bleeding days. Then move to the month of your holiday to look for a possible overlap.
Cycle length
Period length
Ovulation day
Period days logged: 0 days
Tap every day you bled to add or remove it
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You can enter past or future period dates. Past dates inform the calculated rhythm; future entries anchor your plans and remain estimates.
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Move the calendar to your trip and check predicted bleeding. Hover or hold a date for details; the cycle summary stays on today.
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Pack supplies and leave a few flexible days. Save the private link, or add a period reminder using the calendar options.
periods.day has no accounts, cookies, analytics, or saved cycle data. Your entries live only in a link you can share. Nobody else can edit your entries.
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Predicted period dates can move. Bring your preferred supplies even if no overlap is shown, and keep plans flexible. If your periods change or worry you, seek medical advice. Understand irregular periods
You can see a possible overlap between your travel dates and predicted bleeding. It is not a guarantee: cycle length varies, and estimates further into the future are less dependable.
A recent average may hide a wide range of cycle lengths. Keep a larger buffer, pack supplies and avoid booking around one exact date. Seek medical advice if you are concerned about changes.
No. The app only estimates timing. If you want to discuss delaying a period, consult a qualified healthcare professional beforehand; suitable options depend on your medical history.
These estimates use pregnancy data from 221 women who were actively trying for a baby and had stopped using contraception. They recorded each day whether they had intercourse. Li, Wilcox and Dunson (2015, Table 3) used a statistical model to estimate the chance of a clinical pregnancy from one act on a given cycle day. This does not mean the women had sex once every day. The study did not record whether ejaculation occurred inside the vagina. These figures therefore do not estimate the risk with withdrawal. Our calendar shifts the study’s curve to match the calculated ovulation day or the cycle day you set. This is an approximation, not a validated personal prediction. Days before the table starts use its first value. The percentages are population estimates, not your personal odds or a contraceptive method. Li, Wilcox & Dunson (2015)