Knowing the facts of ovulation can help you find your fertile window.
The only time you can get pregnant is when there is a live egg in your fallopian tube and a live sperm swimming to the egg. Since the lifespan of your egg is 24 hours and the lifetime of sperm is five days, you have a fertile window of only six days each month. Other than those six days, your chances of getting pregnant are zero.
Knowing the facts of ovulation can help you find your fertile window. These facts include the timing of your menstrual cycles, changes in your body temperature associated with ovulation, and changes in your cervical mucus caused by ovulation. Also, a hormone appears in your urine one to two days before ovulation. Using these facts, you can find your fertile window.
Fact: Your Average Menstrual Cycle
This fact is a bit hard to find because it is different for different women and may be different for you each month. You need to track your periods for at least 6 months to find your average cycle:
- The first day of your period is day one. The day before your next period is the last day. An average cycle is 28 days. Yours may be a bit shorter or longer.
- If you average about 28 days, the most fertile days for you will be the 12th, 13th, and 14th days of your cycle.
Fact: Cervical Mucus Changes Before Ovulation
Right after your period, your cervical mucus is low. As estrogen starts to build up before you ovulate, cervical mucus increases. This mucus will provide the slippery fluid sperm need to make it through your cervix. Tracking your mucous changes can predict your fertile window:
- At the end of your period, estrogen is low and your vagina feels dry.
- As estrogen increases before ovulation, your vaginal mucous may look creamy.
- As estrogen surges just before ovulation, your vaginal mucus looks stretchy and slippery, like egg white. This will last for about 4 days and these days are your fertile window.
These facts include the timing of your menstrual cycles, changes in your body temperature associated with ovulation, and changes in your cervical mucus caused by ovulation. Using these facts, you can find your fertile window.
Fact: Basal Body Temperature Changes During Ovulation
Right after you release your egg, your resting body temperature – basal body temperature – jumps up by about one-half a degree. This jump is caused by a surge in the hormone progesterone. Knowing this fact, you can tell the day of ovulation. You may want to buy a basal body thermometer at the pharmacy. These thermometers may be more sensitive to small changes in temperature. To find the change:
- Start taking your temperature on the 12th day of your cycle or when your cervical mucus changes.
- Take your temperature in the morning before you get out of bed.
- Take it at the same time each morning.
- Do not smoke or drink the night before, and disregard temperature changes when you have a fever or you have had a poor night’s sleep.
Fact: A Hormone in Your Urine Predicts Ovulation
This fact may be key to the most accurate way to find your fertile window. Luteinizing hormone (LH) is the hormone that actually triggers the release of an egg. It starts to build a few days before ovulation, and surges one to two days before ovulation. During this time, you can detect LH in a urine sample.
This urine test is called an ovulation kit or fertility monitor. You can buy a set of tests at the pharmacy. These kits are close to 100 percent accurate. When your mucus start to change, you can start testing. When you get a positive test, you have started the most fertile part of your fertile window.
With these facts, you can predict your fertile window. The chances of pregnancy occurring during the first three days of your window are about 15 percent. The chances of pregnancy in the last three days of the window are about 30 percent. But just like the lottery, you need to buy a ticket to win, so don’t forget to have sex.