Last updated on Jun 25th, 2015 at 12:10 pm

Everyone’s body is different, and there’s no mathematical formula you can use to accurately determine when your ovulation occurs.

Ovulation: when a mature egg is released from the ovary and travels down the fallopian tube, ready to be fertilized if it meets a sperm cell.

1. Pull out the calendar

Start keeping track of your cycle. Circle the first day of your cycle, which is the day you start your period. Keep track of how many days it lasts.

  • Count the number of days in each cycle, including the day you start your period. The last day of each cycle is the day before your next period starts.
  • Keep track of your cycle this way for a couple of months. The more cycles you have to reference, the more accurate the calendar method will be.

It’s difficult to pinpoint the exact day you’ll ovulate using only a calendar. Instead, a calendar is useful for predicting the range of days during which you will be fertile.

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You can predict the first fertile day in your current cycle by finding the shortest cycle in your chart. Subtract 18 from the total number of days in your shortest cycle. Count that number of days from day one in your cycle (including day one when you count) and mark the day you land on. That day is the first fertile day in your cycle – in other words, the first day in your cycle when you’ll be able to get pregnant.

Similarly, you can predict the last fertile day in your current cycle by finding the longest cycle in your chart. Subtract eleven days from the total number of days. Count that number of days from day one in your cycle (including day one when you count) and mark the day you land on. That day is the last fertile day in your cycle – the last day you’ll be able to get pregnant.

Obviously, your range of fertile days will be shorter or longer depending on your unique cycle.

2. Check your cervical mucous

Check your cervical mucus every day and note the distinct changes that take place over the course of your cycle. Keep track of the changes on your calendar.

  • Chart the days when you have your period, dry days, and days when your mucus is tacky, sticky, slippery, and wet.
  • Note changes in colour and smell in addition to texture. Note whether the mucus is cloudy or clear.
  • Keep as thorough a record as possible, especially in the first few months when you’re still getting used to this method.

It’s important to note that breastfeeding, infections, certain drugs, and other circumstances can affect the cervical mucus, so be sure to note these factors as well.

The day of ovulation is usually the day when cervical mucus is most wet and slippery. In the days that follow that peak, especially when the cervix is dry again, fertility is at its lowest.

3. Start taking your temperature

Buy a basal thermometer (a digital thermometer). Your body temperature is at its lowest during the first part of your cycle and it rises slightly when you ovulate. After that it stays elevated for the rest of your cycle.

Keeping track of your basal body temperature, when your body is completely at rest, over three months or so will reveal patterns that help you predict when you’ll ovulate. Because the incremental temperature change from day to day is so small, regular thermometers shouldn’t be used.

4. Use an ovulation test

Ovulation testing kits are available for sale in drugstores. They test for the presence of Luteinizing Hormone (LH) in your urine, which increases one to two days before ovulation. Similar to over-the-counter pregnancy tests, they are digital devices with a testing stick to be held under your urine stream.

Good to know: Ovulation tests accurately predict the level of LH in urine, but since there’s always a small amount of LH in urine, its presence doesn’t necessarily mean a person is ovulating. For this reason, ovulation tests are generally not considered to be as accurate as other methods of calculating ovulation.

Source: Article provided by wikiHow, a wiki building the world’s largest, highest quality how-to manual. Please edit this article and find author credits at the original wikiHow article on How to calculate your ovulation. Content on wikiHow can be shared under a Creative Commons License.