How accurate is the period prediction?

The prediction is based on average patterns and your typical cycle length. Individual cycles can vary due to stress, health, and lifestyle factors. For best accuracy, track your cycles over several months.

What is the fertile window?

The fertile window is typically the 5 days leading up to ovulation and the day of ovulation itself. This is when conception is most likely to occur.

Can this calculator help with family planning?

Yes, this calculator can help identify your most fertile days for conception. However, it should be used in conjunction with other methods for accurate family planning.

Why does my cycle length vary?

Cycle length can vary due to stress, illness, travel, weight changes, hormonal fluctuations, and other lifestyle factors. Tracking over time helps identify your personal patterns.

When should I see a doctor about my cycle?

Consult a healthcare provider if you experience severe pain, very irregular cycles, no periods for 3+ months, or other concerning symptoms.

How can I use this for natural family planning?

This calculator can help identify your fertile window, but should be combined with other fertility awareness methods like basal body temperature tracking and cervical mucus observation for reliable natural family planning.

Period & Ovulation Calculator

Predict your next period and estimated ovulation window based on your cycle length and last period date.

period calculator

menstrual cycle

ovulation

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Common Cycle Lengths

Typical menstrual cycle lengths for quick estimation

Cycle Information

Enter your menstrual cycle details for prediction

Last Period Date

Cycle Length (days)

Period Length (days)

How it works: Enter your last period start date, typical cycle length, and period length. The calculator estimates your next period, ovulation date, and fertile window based on average patterns.

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