If you are trying for a baby, to increase your chances of conceiving, it helps to know when you are at your most fertile, and when is the best time to have sex.
Your fertile window
Conception is possible during the ‘fertile window’ – the five days leading up to, plus the day of ovulation. The chance of you becoming pregnant is greatest if you have sex during the two days leading up to or on the day of ovulation.
Ovulation happens about 14 days before your period starts.
How you know you’re ovulating
To work out your ovulation day, you need to know how many days there are in your menstrual cycle.
Each woman is different, so to calculate your cycle, count from the first day of your period to the day before your next period.
This chart shows the most fertile days for some menstrual cycles. You can also use this handy fertility calculator on the Your Fertility website to calculate your most fertile period.
Fertility chart
| Length of cycle |
Ovulation day |
Most fertile period |
| 35 days |
Around day 21 |
Days 19, 20 and 21 |
| 32 days |
Around day 18 |
Days 16, 17 to 18 |
| 28 days |
Around day 14 |
Days 12, 13 and 14 |
| 24 days |
Around day 10 |
Days 8, 9 and 10 |
| 21 days |
Around day 7 |
Days 5, 6 and 7 |
Be in tune with your body
Your body changes at different stages of your cycle. A few days before ovulation the vaginal mucus changes and becomes clear and slippery – a bit like egg white and perfect for
sperm to swim along! When you notice this change, it’s time for sex.
Get technology involved
An ovulation predictor kit, available at any pharmacy or supermarket, can be useful. It’s a simple urine test you can use a few days before you ovulate. A positive result means you are likely to ovulate within the next 24 to 36 hours, which is when you should be having sex.
If it’s all too hard
If this all seems too much of a bother, or if your cycle isn’t regular, just make sure you have sex every two to three days. This will give you the best chance of conceiving.
So, get yourself ready for the next fertile window and good luck!
For more information about fertility and ways to increase your chances of having a baby, visit Your Fertility.
Your Fertility is brought to you by the Fertility Coalition: the Victorian Assisted Reproductive Treatment Authority (VARTA), Andrology Australia, Jean Hailes Research Unit, and the Robinson Research Institute.
Your Fertility is a national public education program funded by the Commonwealth Department of Health and the Victorian Department of Health & Human Services.
VARTA
Victorian Assisted Reproductive Treatment Authority
The Victorian Assisted Reproductive Treatment Authority (VARTA) is a statutory authority funded by the Victorian Department of Health and Human Services. VARTA provides independent information and support for individuals, couples and health professionals on fertility and issues related to assisted reproductive treatment. This includes IVF, surrogacy and donor-conception.