What is ovulation?
Each cycle one follicle matures and releases an egg about 24-36 hours after the LH surge. The egg can be fertilised for about 12-24 hours, but sperm can survive up to five days in the female reproductive tract, so intercourse in the days before ovulation can also lead to pregnancy.
Calculating it
Subtract 14 from your cycle length:
- 28-day cycle: around day 14
- 32-day cycle: around day 18
- 26-day cycle: around day 12
Day one is the first day of your period. Our ovulation calculator shows your fertile days, but this is an estimate because cycles vary.
Signs of ovulation
- Cervical mucus becomes clear, slippery and stretchy like egg white.
- LH urine tests: the 1-2 days after a positive result are most fertile.
- Basal body temperature rises 0.3-0.5 °C after ovulation, confirming it in retrospect.
- Mild one-sided pelvic pain in some women.
How often to have sex
Every day or every other day in the fertile window is ideal. Focusing only on ovulation day can cause stress; regular intercourse every 2-3 days throughout the cycle also covers the fertile days.
When to see a doctor
Seek assessment after one year of trying under 35, or six months at 35 or over. Women with very irregular cycles (such as PCOS), those over 40 or with a known fertility problem should come earlier. Follicle tracking by ultrasound shows precisely whether and when ovulation occurs.
Frequently Asked Questions
How do I know when I ovulate with irregular periods?
When should we have sex after a positive ovulation test?
Sources
- Practice Committee of the ASRM. Optimizing natural fertility: a committee opinion. Fertil Steril, 2022.
- Wilcox AJ, et al. Timing of sexual intercourse in relation to ovulation. N Engl J Med, 1995.
The information on this website is for general information only and does not replace a medical consultation.
