If you are trying to become pregnant, your chances will be improved if you have sex at a particular time of your cycle. Knowing when you ovulate – when an egg is released from your ovaries – is the key to knowing when that right time is.
When you are most fertile
The 5 days before ovulation, together with the day you ovulate, are the days when you are most likely to conceive. Sperm can live up to 5 days inside your body, so if you have sex up to 5 days before your egg is released, you can get pregnant. After ovulation, though, your egg can only live for 12 to 24 hours. After this time is up, your time for getting pregnant has gone for now till the following month.
Your chances of getting pregnant are at their highest in the 3 days leading up to and including ovulation.
Ovulation usually happens about halfway through your menstrual cycle, about 14 days before the first day of your next period, but the exact time can vary. Although signs that you are about to ovulate can be subtle, there are some things you can pay attention to and track over time to help you predict your fertile window.
Changes in mucus
Noticing how your vaginal secretions change during your menstrual cycle is the basis of the Billings ovulation method. Around the time of ovulation, you may notice your secretion is clear, stretchy and slippery — similar to egg whites. After ovulation, when the chances of becoming pregnant drop, the secretion tends to become cloudy and thick, or disappear entirely.
Changes in body temperature
When you’ve just ovulated, your body temperature may increase very slightly, by about half a degree Celsius. If you’re using temperature as a means of keeping track of when you are most fertile, you need to use a special thermometer to take your temperature every morning before you get out of bed. If you record the readings every day using a graph or a spreadsheet, it’s possible to learn your pattern over time. The time when you are most fertile is 2 to 3 days before the rise in temperature.
There may be other signs that you are near the time of ovulation, such as mild abdominal cramps, breast tenderness or increased sex drive. However, using these signs to predict when you’re fertile is not the most reliable method.
Using ovulation calculators and kits
Ovulation calendars and kits can also help you predict ovulation.
Ovulation calendars are available on websites such as www.yourfertility.org.au, and use the date of your last period and the length of your cycle to predict when you are likely to be most fertile.
Home ovulation predictor kits are available from pharmacies. You use the kit a few days before your predicted ovulation day, to test for a rise in the level of a hormone called luteinising hormone (LH) in your urine. A positive result indicates you will ovulate within the next 24 to 36 hours.
A blood test, which your doctor can order, can also detect ovulation by measuring levels of the hormone progesterone.
For more information and support, call Pregnancy, Birth and Baby on 1800 882 436.
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Last reviewed: July 2020