The general rule is that women ovulate fourteen days before their next period. A normal menstrual cycle will last between twenty-three and thirty-five days. (If your cycles are shorter or longer, you may want to consult an expert.) But because a woman’s body varies from month to month, few women have the exact same number of days every cycle. And because sperm can live for two to three days after intercourse and the egg can survive for only twelve to twenty-four hours after ovulation, the best time to have intercourse is one to three days before ovulation.
The good news is that if you’ve just started trying to have a baby, relax and enjoy your baby-making efforts.
“If you have a low risk of infertility—are not overweight, are not over thirty-five, and are healthy—typically I tell my patients to have sex fourteen days before their period should begin. If you do this each month, most likely, you’ll become pregnant within a year,” says Kristen N. Innes, M.D., P.A., an obstetrician in Frisco, Texas. If you’ve been trying for a while or want to get pregnant quickly, there are plenty of tools to help you. Here’s a breakdown of the most popular free and over-the-counter methods available to predict ovulation:
Charting Basal Body Temperature (BBT) A woman’s body temperature drops when there is a rise in the luteinizing hormone (LH), which helps regulate egg production. Body temperature goes up significantly when LH levels out. This elevation in temperature indicates that ovulation has occurred. To chart your BBT, you need a basal body thermometer, available at most drugstores for $10 to $13, and a chart to track your temperature readings. You must take your temperature first thing every morning, before getting out of bed. You’re looking for a slight drop or, more likely, a significant rise.
Pros: Charting your BBT over a period of a few months will enable you to learn about your cycle. It’s also inexpensive.
Cons: “The Basal Body Temperature tells you when you have finished ovulating, so if you’re trying to find out when you’ll ovulate in order to conceive, it isn’t terribly helpful,” says Kristen. It also can’t precisely predict the next month’s ovulation date as the days vary each month.
Checking Cervical Mucus (CM) As the estrogen level rises in the first half of your cycle, your mucus changes from sticky to creamy to a thin, watery, stretchy consistency. Ovulation occurs when this thin, stretchy discharge is present. To do this, simply check your mucus in the morning or throughout the day to determine the thickness and texture. Once you detect this watery CM, you should have sex every day, or every other day, until the slippery CM disappears.
Pros: It’s free, and if done accurately, can tell you when you’re about to ovulate.
Cons: Not all women can tell the difference in the thickness of their mucus.
Ovulation Predictor Kits (OPKs) OPKs use special chemicals to recognize a surge of LH in your urine, indicating that ovulation will occur in about twenty-four to thirty-six hours. The kits, found in most drugstores, cost between $25 and $30. You simply follow the directions on the package and have intercourse on the day of the surge and the day after.
Pros: They’re easy to use and accurate. In fact, Kristen recommends that her patients use them. “If you want to be scientific about it and know for sure, I’d suggest using these every morning.”
Cons: They don’t work for everyone. According to some physicians, a small percentage of women will actually have false positive results.
Clearblue Fertility Monitor At $200 to $250 per monitor, plus $50 for test sticks—it’s the Ferrari of ovulation kits. The Clearblue Fertility monitor checks for the presence of two hormones: LH and estrogen metabolite. To use, urinate on a stick every morning starting at day six or nine of your cycle, then place the stick in the monitor for a reading of high, low, or peak fertility.
Pros: It’s very reliable, easy to use, and pinpoints your most fertile days.
Cons: It’s expensive.
Cycle Beads This necklace of white and brown beads, with one red bead, represents the days of your menstrual cycle. By moving a black band over the top of each bead, you can see your most fertile times in your cycle.
Pros: It’s fairly easy to use and can be purchased online for $14.
Cons: Women don’t always remember to move the ring daily and it doesn’t pinpoint the exact date of ovulation.