What is Ovulation?

Ovulation is when a mature egg is released from the ovary, usually around day 14 of a 28-day menstrual cycle (counted from first day of last period). The fertile window is the 5-6 days when pregnancy is most likely — the 5 days before ovulation plus the day of ovulation itself. Sperm survive in the reproductive tract for up to 5 days; the egg lives 12-24 hours after release.

How to use

1. Enter LMP date — First day of your last menstrual period
2. Enter cycle length — Days from one period start to next (typically 28)
3. View ovulation date — Estimated day egg is released
4. View fertile window — Best days for trying to conceive

Formula

Ovulation Day = LMP + (Cycle Length – 14)

For 28-day cycle: day 14. For 30-day cycle: day 16. For 26-day cycle: day 12.

Fertile Window: 5 days before ovulation + day of ovulation

Tips

• Track cycles for 3-6 months for accurate cycle length
• Ovulation predictor kits (OPKs) confirm timing more accurately
• Basal body temperature rises 0.5°C after ovulation
• Cervical mucus becomes egg-white-like before ovulation
• If trying to conceive: regular intercourse throughout fertile window

FAQs

How accurate is this calculator?

Reasonable estimate for women with regular cycles. For irregular cycles, use ovulation predictor kits or fertility monitoring devices for accuracy.

Can I get pregnant outside fertile window?

Very low probability but not zero. Sperm can survive 5 days; ovulation timing varies. The further from fertile window, lower the chance.

Why is my cycle irregular?

Common causes: stress, weight changes, PCOS, thyroid issues, breastfeeding, perimenopause. Persistent irregularity — consult gynecologist.

Best app for fertility tracking?

Flo, Clue, Glow, Natural Cycles — track period, cervical mucus, temperature for accurate ovulation predictions over time.

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