What happens to cycle-synced reminders if my cycle is irregular?

Bottom lineCycle-synced reminders use your period prediction, so if you have no logged period the app asks you to log one first, and if you have periods but no prediction it estimates from your last period plus your average cycle length; each period you log realigns future reminders, and a slightly wider window helps if your cycle runs early or late.

Cycle-synced reminders rely on your period prediction, so they get more accurate the more you log - and they are designed to cope gracefully when your cycle is not perfectly regular.

How the fallback works

• If you have no logged period yet, the app will not guess - it prompts you to log a period to activate cycle-synced reminders.
• If you have logged periods but no formal prediction yet, Femora estimates from your last period start plus your average cycle length (defaulting to 28 days if there is not enough history).
• Each new period you log nudges future windows back into alignment, so reminders self-correct over time.

Tips for irregular cycles

• Log every period - this is what keeps the prediction (and your reminders) accurate.
• Consider a slightly wider window so a dose is not missed if your period comes a few days early or late.
• Use pause mode during a break instead of deleting the medication.

If your cycles are very irregular, that is worth raising with a clinician - both for the cause and to agree on a medication-timing plan. See what causes irregular periods.

This is general information, not medical advice.