Ovulation

Ovulation is the release of a mature egg from an ovary. The egg may be released by either ovary and will slowly make its way down a fallopian tube toward the uterus. It can survive only 12 to 24 hours after it is released before it begins to dissolve and is reabsorbed into the body or passed with the next menstrual period; that is, unless it is fertilized by one lucky and very fast sperm.

Ovulation usually occurs around the middle of your cycle; however, it can occur on a different day each month, so it's important you learn how to track your cycle in order to predict your ovulation. The first day of your period is said to be Day 1 of your cycle and ovulation usually occurs between Day 11 and 21. The average cycle length is between 28 and 32 days; however, many women have cycles that are longer or shorter - another good reason to track your individual cycle.

The first part of your cycle is called the follicular phase and continues until you ovulate. The second half of the cycle is called the luteal phase and lasts from the day of ovulation until the first day of the next period. The follicular phase can last anywhere from 7 days to 40 days, but the luteal phase is a little more precise, lasting 12 to 16 days. So the day you ovulate is what determines the length of your cycle. Sometimes your body fails to release an egg, called an anovulatory cycle, even though you still get your period, so don't rely on your period to tell you whether you are ovulating.

If you are trying to get pregnant, you can increase your chances of conception by knowing when you are most fertile and having intercourse frequently around that time. You are most fertile just before ovulation and should have intercourse one to two days before the egg is released, and up to about 24 hours after, because sperm can live for two to three days in your body. If fertilized, the egg will take approximately 6 to 12 days to reach the uterus where it will implant and begin to divide and grow.

There are several ways to predict when you will ovulate:

Basal Body Temperature: When an egg is released from an ovary, your body begins producing progesterone, which - if the egg is fertilized - will sustain the pregnancy until the placenta forms and takes over. This boost in progesterone causes your body temperature to rise ever so slightly - 0.4 to 1.0 degrees. You cannot feel such a miniscule rise, but a very sensitive thermometer, called a basal body temperature (BBT) thermometer, can detect it. You are most fertile approximately two or three days before your temperature spikes, so you need to learn to spot the signs that your temperature is about to spike (usually a slight dip in your temperature). This is best done by taking your BBT every morning for several months and charting your temperature to reveal patterns. To learn more about how to track your BBT, click here

Cervical Mucus: Cervical mucus is the viscous fluid secreted by the cervix. For most of the month, it is too thick and dry for sperm to swim through; however, as you near ovulation, the consistency of your cervical mucus changes to become clear, slippery and stretchy, kind of like raw egg whites. This fluid is easy for sperm to swim through on their way to your fallopian tubes and your awaiting egg. Begin testing your cervical mucus every day and charting it much like you do your BBT. To learn more about testing your cervical mucus, click here

Position and Firmness of Cervix: The position and firmness of your cervix changes over the course of your cycle. Just after your period, your cervix is low, firm and closed. As you near ovulation, it will be soft, wet, higher and more open. (If you have given birth before your cervix may feel more open than someone who has not.) After ovulation, your cervix will slowly return to a lower, firmer, more closed position. To learn more about monitoring the position and firmness of your cervix, click here

Mittelschmerz: This German term refers to the slight abdominal discomfort one in five women feels during ovulation. Some women experience it every month while others only experience it occasionally. Usually it is centered on just one side of the abdomen, can last anywhere from a few minutes to a few hours, and may range from mild achiness to twinges of pain.

Predictor Kits: Ovulation predictor kits are available over-the-counter at most drugstores and detect the surge in luteinizing hormone (LH) that occurs just before ovulation. They are more reliable than charting your BBT and are able to predict ovulation 12 to 36 hours in advance, giving you a better chance of conceiving. However, it is possible for you to experience a surge in LH without ovulating, so you may get a false-positive reading, and the kits are expensive, ranging in price from $20 to $50.