Understanding Ovulation: Timing for Conception
Published Apr 13, 2026 · 6 min read
Ovulation occurs once per cycle, typically 14 days before your next period. The fertile window is about 6 days: 5 days before ovulation plus ovulation day.
The Fertile Window
Sperm can survive up to 5 days in the reproductive tract. The egg survives 12-24 hours after release. This creates a 6-day fertile window, but the highest probability days are the 2 days before ovulation.
Tracking Methods
- Calendar method — Track cycle length for 6+ months, estimate ovulation 14 days before expected period
- Basal body temperature (BBT) — Temperature rises 0.5-1°F after ovulation
- Ovulation predictor kits (OPKs) — Detect LH surge 24-36 hours before ovulation
- Cervical mucus — Becomes clear, stretchy (egg white consistency) near ovulation
Conception Probability by Timing
| Day Relative to Ovulation | Probability |
|---|---|
| -5 days | ~4% |
| -3 days | ~15% |
| -1 day | ~25-30% |
| Ovulation day | ~20-25% |
| +1 day | ~5% |
Try it: Use our Ovulation Calculator to estimate your fertile days based on your cycle length.