Health Calculator - Cycle Tracking

Period Tracker Online India

Estimate your next period, ovulation date, fertile window, and upcoming cycles. All calculations happen in your browser.

Adults only: This tool is designed for adults aged 18 and above. If you are younger and worried about irregular periods, please speak with a parent, guardian, or a qualified doctor.

Indian context for cycle tracking

Period timing can vary because of stress, illness, travel, thyroid issues, PCOS, and other hormonal changes. Indian women also have high rates of PCOS and cycle irregularity, so this tool is a guide, not a diagnosis.

Privacy note: No dates are stored. Refresh the page and all data is cleared.

Enter your cycle details

Next Period

Days Until

Cycle Prediction
Ovulation
Fertile window
Next 3 cycles
Clinical Context

Enter your cycle details to see how your selected cycle length fits the usual adult 21 to 45 day reference range.

Medical Disclaimer: This calculator is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making health decisions. Results are estimates and may not apply to every individual.

How this period tracker works

This tracker estimates your next period by adding your average cycle length to the start date of your last period. It estimates ovulation as roughly 14 days before the next predicted period, then calculates a fertile window around that date.

The important edge case is late periods. If the first predicted next period has already passed, this tool keeps moving forward cycle by cycle until it finds the next future date. That way it never shows a past date as your next upcoming period.

What late-period messages mean

A period that is 1 to 7 days late can still be within normal cycle variation. Around 8 to 14 days late, many clinicians would suggest considering a home pregnancy test if pregnancy is possible. More than 14 days late deserves medical attention, especially if the delay is new or repeated.

Late periods are not always caused by pregnancy. Stress, illness, travel, weight change, intense exercise, thyroid problems, and PCOS can all shift cycle timing.

When to speak with a doctor

Consider a medical review if:

  • Your cycle is frequently outside the adult 21 to 35 day range or highly unpredictable.
  • You are repeatedly more than 14 days late and pregnancy is not the explanation.
  • You have very painful, very heavy, or very infrequent periods.
  • You also have acne, weight gain, excess hair growth, or scalp hair loss - those may point toward PCOS.

Medical Sources

  1. ACOG. Abnormal Uterine Bleeding FAQ and patient guidance for typical cycle timing in adults.
  2. FIGO / contemporary gynecology references describing normal-cycle variability in reproductive-age adults.