When does ovulation happen?
In regular cycles, ovulation occurs about 14 days before the next period: usually day 14 in a 28-day cycle and around day 18 in a 32-day cycle.
Which days are fertile?
Sperm can survive up to 5 days in the female reproductive tract, while the egg can be fertilised for about 12-24 hours. The fertile window therefore covers the 5 days before ovulation and ovulation day. Couples trying to conceive are advised to have intercourse every other day during this time.
Other ways to detect ovulation
- Ovulation (LH) test kits
- Clear, slippery cervical mucus
- A slight rise in basal body temperature after ovulation
- Follicle tracking by ultrasound
If you have not conceived after one year of regular intercourse (six months if you are 35 or over), an infertility assessment is recommended.
Frequently Asked Questions
Does intercourse during the fertile window mean I will conceive?
No. Even for healthy young couples, the chance of pregnancy per cycle is about 20-25%. It is normal for it to take several months.
Can this method be used for contraception?
No. Ovulation can vary from cycle to cycle, so the calendar method is not a reliable form of contraception.