Simply log the start date of your period using the form or by clicking a date on the calendar. The tracker calculates your average cycle length based on your history and predicts your next period, ovulation day, and fertile window. All calculations use established methods: ovulation typically occurs 14 days before your next period, and the fertile window spans 5 days before ovulation plus ovulation day itself.

Yes, 100%. All your period data is stored exclusively in your browser's local storage (localStorage). No data is ever sent to any server, cloud service, or third party. This means your intimate health information remains completely under your control. You can delete all data at any time with one click, or export it for backup. We have no access to your data whatsoever.

Cycle length is the number of days from the first day of one period to the first day of the next period. For example, if your period starts on January 1st and your next period starts on January 29th, your cycle length is 28 days. The tracker averages your last several recorded cycles to give the most accurate prediction. If you have fewer than 2 recorded cycles, it uses the default 28-day cycle length which you can adjust in settings. The more cycles you log, the more accurate the predictions become.

Ovulation is when an ovary releases an egg — typically about 14 days before your next period starts. The fertile window is the 6-day period when pregnancy is most likely: the 5 days leading up to ovulation plus ovulation day itself. Sperm can survive in the body for up to 5 days, so intercourse before ovulation can still result in pregnancy. This tracker estimates these dates based on your cycle data, but please note this is an estimation and should not be used as a sole method of contraception or conception planning. Consult a healthcare provider for personalized advice.

If your cycles vary significantly (e.g., ranging from 25 to 35 days), the predictions will be less precise because they're based on averages. The tracker still provides useful estimates, but you should log each period consistently to help refine the calculations. If your cycles are consistently irregular (varying by more than 7-9 days), consider consulting a healthcare provider, as this could indicate underlying conditions like PCOS, thyroid issues, or stress-related hormonal changes. This tool is for tracking purposes and does not replace professional medical advice.

Absolutely! Click the download icon () in the History section to export all your records as a JSON file. You can save this file as a backup or transfer it to another device. To restore, click the upload icon () and select your backup file. This gives you full ownership and portability of your health data.

Tracking symptoms like cramps, headaches, bloating, or mood swings helps you identify patterns in your cycle. Over time, you may notice that certain symptoms consistently appear at specific phases — for example, headaches during the luteal phase or bloating right before your period. This awareness can help you prepare, manage symptoms proactively, and provide valuable information to share with your healthcare provider during appointments.

This tracker provides estimates only based on average cycle patterns. It should not be relied upon as a primary method of contraception or as a guaranteed fertility predictor. Real ovulation timing can vary due to stress, illness, travel, and many other factors. For contraception, consult a healthcare provider about reliable methods. For pregnancy planning, this tool can help identify your likely fertile window, but combining it with ovulation test kits or basal body temperature tracking will yield more accurate results.