Guides
Short, plain-language answers about period tracking, with links to the NHS and ACOG pages they're based on.
- AccuracyHow accurate is a period tracker?What a calendar-based period tracker can predict, why it sometimes misses, and how to get better predictions.4 min read
- Irregular cyclesTracking irregular periodsTrack irregular periods for free and see a realistic date range based on your own cycles, not a single guess.4 min read
- Fertile windowWhat does “fertile” mean on a period tracker?What the fertile window on a period tracker shows, how it’s calculated, and why the other days aren’t “safe days”.3 min read
- OvulationWhat does ovulation mean on a period tracker?Why the ovulation day on a period tracker is an estimate, how it’s placed on the calendar, and what it can’t tell you.3 min read
- Choosing a trackerPeriod tracker app or online tracker?Free period tracker apps compared with browser-based trackers: accounts, where your data is stored, and what you give up.4 min read
- PrivacyIs a period tracker safe for your data?What happens to the dates you enter in a period tracker, what to check before using one, and how Period Tracker Free stores your data.5 min read