During each monthly cycle, healthy couples in their 20s or early 30s who aren’t using birth control have a 20 percent chance of getting pregnant. And that’s a surprisingly high percentage considering that you can conceive only around the time of ovulation — a small window of opportunity each month (usually about 12 to 24 hours) during which the egg is viable, or open for the business of fertilization.
Here are five ways to help you pin down the big day.
WHEN DOES OVULATION USUALLY OCCUR?
Ovulation usually occurs halfway through your menstrual cycle — the average cycle lasts 28 days, counting from the first day of one period (day one) to the first day of the next period. But as with everything pregnancy-related, there’s a wide range of normal here (anywhere from 23 to 35 days), and your own cycle may vary slightly from month to month.
HOW DO I KNOW IF I’M OVULATING?
1. Check the calendar: Keep a menstrual calendar for a few months so you can get an idea of what’s normal for you or use tools that can help you calculate ovulation. If your periods are irregular, you’ll need to be even more alert for other signs of ovulation, so read on.
2. Listen to your body: If you’re like 20 percent of women, your body will send you a memo when it’s ovulating, in the form of a twinge of pain or a series of cramps in your lower abdominal area (usually localized to one side — the side you’re ovulating from). Called mittelschmerz — German for “middle pain” — this monthly reminder of fertility is thought to be the result of the maturation or release of an egg from an ovary. Pay close attention, and you may be more likely to get the message.
3. Chart your temperature: That is, your basal body temperature, or BBT. Taken with a special thermometer (yes, you guessed it, a basal body thermometer), your BBT is the baseline reading you get first thing in the morning, after at least three to five hours of sleep and before you get out of bed, talk, or even sit up. Your BBT changes throughout your cycle as fluctuations in hormone levels occur. During the first half of your cycle, estrogen dominates. During the second half of your cycle (once ovulation has occurred), there is a surge in progesterone. Progesterone increases your body temperature as it gets your uterus ready for a fertilized, implantable egg. Which means that in the first half of the month, your temperature will be lower than it is in the second half of the month, after ovulation.
Your BBT will reach its lowest point at ovulation and then rise immediately and dramatically as soon as ovulation occurs. Keep in mind that charting your BBT for one month will not enable you to predict the day you ovulate but rather give you evidence of ovulation after it has occurred. Charting your BBT over a few months, however, will help you to see a pattern to your cycles, enabling you to predict when ovulation will occur in future months — and when to hop into bed accordingly.
4. Get to know your cervix: Ovulation isn’t an entirely hidden process. As your body senses the hormone shifts that indicate an egg is about to be released from the ovary, it begins to ready itself for the incoming hordes of sperm and give the egg its best chance of getting fertilized. One detectable sign of oncoming ovulation is the position of the cervix itself. During the beginning of a cycle, your cervix that neck-like passage between your vagina and uterus that has to stretch during birth to accommodate your baby’s head — is low, hard, and closed. But as ovulation approaches, it pulls back up, softens a bit, and opens just a little, to let the sperm through on their way to their target. Some women can easily feel these changes, while others have a tougher time. Check your cervix daily, using one or two fingers, and keep a chart of your observations. The other cervical sign you can watch for is the appearance, increase in quantity, and change in consistency of cervical mucus. Its more noble purpose is to carry the sperm to the ovum deep inside you.
After your period ends, you’ll have a dry spell, literally; you shouldn’t expect much, if any, cervical mucus. As the cycle proceeds, you’ll notice an increase in the amount of mucus with an often white or cloudy appearance and if you try to stretch it between your fingers, it’ll break apart. As you get closer to ovulation, this mucus becomes even more copious, but now it’s thinner, clearer, and has a slippery consistency similar to an egg white. If you try to stretch it between your fingers, you’ll be able to pull it into a string a few inches long before it breaks. This is yet another sign of impending ovulation as well as a sign that it’s time to get out of the bathroom and get busy in the bedroom. Once ovulation occurs, you may either become dry again or develop a thicker discharge. Put together with cervical position and BBT on a single chart, cervical mucus can be an extremely useful tool in pinpointing the day on which you are most likely to ovulate and it does so in plenty of time for you to do something about it.
5. Buy an ovulation predictor kit: Don’t want to mess around with mucus? You don’t have to these days. Ovulation predictor kits (OPKs) are able to pinpoint your date of ovulation 12 to 24 hours in advance by looking at levels of luteinizing hormone, or LH, which is the last of the hormones to hit its peak before ovulation actually occurs. All you have to do is pee on a stick and wait for the indicator to tell you whether you’re about to ovulate.
Another option is a saliva test, which takes a peek at levels of estrogen in your saliva as ovulation nears. When you’re ovulating, a look at your saliva under the test’s eyepiece will reveal a microscopic pattern that resembles the leaves of a fern plant or frost on a windowpane. Not all women get a good “fern,” but this test, which is reusable, can be cheaper than those sticks you have to pee on. There are also devices that detect the numerous salts (chloride, sodium, potassium) in a woman’s sweat, which change during different times of the month. Called the chloride ion surge, this shift happens even before the estrogen and the LH surge, so these tests give a woman a four-day warning of when she may be ovulating, versus the 12-to-24-hour one that the standard pee-on-a-stick OPKs provide.
The key to success in using this latest technology is to make sure to get an accurate baseline of your ion levels (currently, there’s a device on the market that needs to be worn on the wrist for at least six continuous hours to get a proper baseline). No OPK can guarantee that you will get pregnant or that you’re actually ovulating; they can only indicate when ovulation may be occurring. So no matter which device or method you choose, patience and persistence are key! Just don’t forget to put together a candlelit dinner, draw a warm bubble bath, or plan a romantic weekend getaway — whatever it is that puts you and your partner in a baby-making mood.
Good luck — and have fun trying!
Ohk