Period Tracker Calendar 2026 | Menstrual Cycle Prediction & Fertility Window
Free Period Tracker 2026. Track menstrual cycles, predict next period, identify fertility window, and log symptoms. Accurate cycle predictions with offline access. 50M+ women trust period trackers.
Period Tracker
Privacy: Your cycle data is stored locally on your device. We don't store or access this information.
About Period Tracker
Track your menstrual cycle with our free, private period tracker. Predict your next period, identify your fertility window, and monitor cycle changes. Over 50M women worldwide use period trackers for reproductive health awareness. All data stays on your device—complete privacy.
Features:
- Accurate cycle predictions based on your pattern
- Fertility window identification for pregnancy planning
- Ovulation date calculation
- Fully offline (no data uploaded)
- Mobile-optimized for on-the-go tracking
Frequently Asked Questions
Clear answers to common questions to help you use this calculator confidently.
How accurate is period tracking?
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How accurate is period tracking?
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Period tracker accuracy depends on cycle regularity. Cycles vary 21-35 days normally. Most women (65-70%) have accurate predictions within 2-3 days. Irregular cycles (PCOS, stress, hormonal changes) may be less predictable. Track 3+ cycles for best accuracy.
What is a normal menstrual cycle?
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What is a normal menstrual cycle?
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Normal cycle: 21-35 days. Average: 28 days. Period duration: 2-7 days. Regular cycles are typical but variation is normal. If cycle changes drastically (>7 days difference), consult a doctor.
When is my fertility window?
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When is my fertility window?
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Fertility window: 5 days before ovulation to 1 day after (6-day window). Ovulation typically occurs 14 days before next period. Sperm can survive 5 days; egg survives 12-24 hours after ovulation. Peak fertility: 2-3 days before ovulation.
What affects menstrual cycle length?
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What affects menstrual cycle length?
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Factors affecting cycle: stress, weight changes, exercise intensity, hormonal birth control, hormonal disorders (PCOS, thyroid), medications, travel, illness, caffeine, sleep. Large stressors can delay period by 1-2 weeks.
Is this a pregnancy detector?
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Is this a pregnancy detector?
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No. This tracks menstrual cycles only. For pregnancy detection, use pregnancy test (HCG). Pregnancy test accuracy: 99% after missed period. Some signs: missed period, nausea, breast tenderness, fatigue.
Can I use this while on contraception?
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Can I use this while on contraception?
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With hormonal contraception (pill, patch, ring): Cycle becomes artificial (no real ovulation). Tracker shows withdrawal bleeding predictability, not fertile window. For fertility awareness, use non-hormonal contraception.
What is PCOS and does it affect tracking?
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What is PCOS and does it affect tracking?
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PCOS (Polycystic Ovary Syndrome): Hormonal disorder causing irregular cycles (35-90+ days). Ovulation unpredictable. Standard trackers less accurate. Consult gynecologist for PCOS management.
Should I track symptoms?
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Should I track symptoms?
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Yes! Track: flow intensity, cramping, mood, energy, headaches. Helps identify patterns. Common PMS symptoms: bloating, mood changes, fatigue, food cravings 1-2 weeks before period.
Is my data private?
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Is my data private?
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Yes. Data is stored locally on your device. We don't collect, store, or send your cycle data to servers. No account required. Your privacy is protected.
Need more help? Contact support or email support@globalcalqulate.com
We typically reply within 24–48 hours.