What's a fertile window?
Your fertile window refers to the most fertile days in your menstrual cycle which give you the highest chance of conceiving.
The most fertile days in your cycle are the days leading up to ovulation, before the egg is released from the ovary. After ovulation the egg survives for just 24 hours, while sperm retain fertilising capability for two to three days in the fallopian tubes. For this reason, we recommend that couples have sexual intercourse every two days throughout the fertile window.
If you’re trying to fall pregnant, the timing of when you and your partner have sex is critical. Our online ovulation calculator can help you understand your fertile window.
How to calculate your fertile window
To calculate your fertile window, you need to determine what day you ovulate. To do this, you need to know the length of your menstrual cycle (which tends to vary from 23 to 35 days).
The length of your menstrual cycle is the number of days from the first day of bleeding in your last period, to the first day of bleeding in your next. From this figure, subtract 14 days from the end of your current cycle to determine the approximate day you ovulate.
What if I have irregular menstrual cycles?
If you have irregular menstrual cycles, or your cycle length varies from month to month, it will be difficult to calculate your ovulation date. Ovulation urine tests or ovulation tracking may be useful, and you should consider seeking further advice from your GP or a Fertility Specialist.
How long should I try for, before seeking specialist advice?
It is recommended that you consider seeking professional advice after trying to conceive naturally without success for 12 months if you are under 35 years-old or after 6 months if you are over 35.
Bulk billed ovulation cycle tracking
Ovulation cycle tracking can help you confidently understand your fertile window by tracking your hormone cycle and detecting the hormone surge associated with ovulation. Read more about ovulation cycle tracking...
Want to know more?
If you want to know more about the menstrual cycle, read about female reproduction….