Medically Reviewed By
MBBS (Col), MD (Col) ยท SLMC No. 27329
Consultant Physician ยท Sineth Hospitals, Boralasgamuwa
Record your recent period dates to estimate average cycle length, next period and ovulation
Enter the first day of each recent period. The tracker will calculate your average cycle length and use that to estimate your next expected period, ovulation date, and fertile window. Recording at least 3 cycles gives a more reliable estimate.
Cycle length is the number of days from the first day of one period to the first day of the next. The average cycle is 28 days, but a normal range is considered to be 21โ45 days. Cycle length can vary from month to month and changes over a lifetime.
All data you enter is stored only in your browser's local storage on your own device. Nothing is transmitted to any server. If you clear your browser data or use a different device or browser, the data will not be available. You can delete individual entries or clear all data at any time using the buttons in the tracker.
Cycle-based estimates assume ovulation occurs approximately 14 days before the next expected period. This is not accurate for everyone. Factors including stress, illness, age, hormonal conditions, breastfeeding, weight changes, and medications can shift ovulation significantly. Calendar-based estimates should not be relied upon as a contraceptive method or as a guaranteed fertility prediction.
Seek medical advice if your periods are frequently irregular, if they stop unexpectedly, if you experience very heavy bleeding or severe pain, or if you have difficulty conceiving after trying for 12 months (or 6 months if over 35).