When Do I Ovulate

From ovulation prediction kits (OPKs) and fertility monitors to fertility charting, there are several ways to help determine when you are likely to ovulate and be fertile during your cycle, each discussed in more detail below.

Ovulation Predictors (OPKs)

The most common type of home-testing kit to predict fertility is the urine-based stick, or ovulation predictor kit (OPK). OPKs work by detecting a high level, also called a 'surge', of luteinizing hormone (LH) in your urine.

Once this LH surge is detected, the assumption is that ovulation is just around the bend.

Luteinizing hormone plays a large part in ovulation, the release of an egg from the ovary. When a woman's pituitary gland gets the signal that an egg is mature and ready, the pituitary releases a surge of LH that lasts only briefly.

OPKs are chemical-coated plastic sticks or wands that are activated when a woman urinates on a specified end. Makers of OPKs recommend that a woman use these products later in the day, from afternoon to evening, and that she reduce her liquid intake for about two hours before testing in order to avoid watering down the results. It is generally believed that ovulation will occur approximately 36 hours after the LH surge.

People who are trying to get pregnant should then have intercourse on the day of and for several days following the detected surge (a positive OPK test). This will promote the presence of sperm in the fallopian tube when the egg is finally released.

In order to know when to use an OPK, a woman must know the approximate and average length of her menstrual cycles. Because the LH surge is only detectable for a brief time, it is very important that test users follow the manufacturers' instructions exactly in scheduling their use of an OPK.

Women who are using fertility medication or other types of hormonal drugs (such as birth control pills) should consult their health practitioner about the usefulness of OPKs in their situation. Some drugs can influence the results, causing false positives.

Fertility Monitors

Fertility monitors are complex electronic machines that look at several indicators to analyze data and help a woman gauge her level of fertility at any given time in her cycle, not only during her time of ovulation.

For example, the ClearBlue Fertility Monitor detects two hormones, estrogen and LH, and is designed to identify all of the fertile days of your cycle, thereby maximizing your chances of getting pregnant. ClearBlue Fertility Monitor can identify not only your 2 Peak Fertility days, but 1 to 5 days of High Fertility preceding Peak, an extremely helpful fertility tool since sperm can live from 3 to 5 days in fertile cervical mucus. The ClearBlue Fertility Monitor relies on disposable urine sticks to detect varying levels of estrogen and luteinizing hormone.

Fertility monitors guide the user as to when to test, based not only on the initial information put into the machine's computer, but also on any personal patterns detected by previous uses of the monitor. Fertility monitors aim to provide a woman with a larger window of fertile opportunity for conception during each cycle.

Saliva-based Ferning microscopes

There's been a recent increase in the use of optical devices to predict a woman's fertility. These mini-microscopes are used to view a sample of the woman's saliva. The devices work by allowing detection of a particular pattern, called "ferning," which is caused by salt crystals in the sample. The crystals form a distinct fern-like appearance only prior to and during ovulation due to an increase in estrogen.

While the science behind this ferning phenomenon is several decades old, it was 2001 before the first optical viewer was approved in the United States. Similar devices have been in use in Europe for many years.

Several different brands of scopes are available: some are smaller and more convenient than others, some allow a woman to track more than one day's results, some resemble miniature microscopes and others are shaped like a lipstick. They all work virtually the same - the woman takes a small sample of either her saliva and puts it on either a slide or directly on the scope's viewer, waits a few seconds or minutes for the sample to dry, and views the sample through a magnifying scope. When the woman sees fern-like structures formed by the crystals in her sample, she is assumed to be near ovulation.

While ferning-scopes can help a woman predict her most fertile time, reading the results correctly can be challenging. There are some non-ferning crystal formations that may be viewed during other, less fertile times of a woman's cycle. Users of these devices will need to become very familiar with the specific type of crystal formations that are known as the 'fern effect.' In addition to information provided by the manufacturer, there are a number of websites with explicit and helpful instructions on reading ferning-scopes.

One of the benefits of ferning scopes is that they are re-usable, so that consumers can re-test with the same scope through many reproductive cycles.

The Fertility Awareness Method

The Fertility Awareness Method (FAM) refers to a few simple techniques that any woman can learn. Performing FAM regularly can help a woman understand and predict her body's reproductive cycles. There are three primary fertility indicators to be aware of and to monitor:

Basal body temperature (BBT) is the temperature of your body immediately upon waking up, before you've done any physical activity at all. You can use any type of thermometer to take your temperature, but many women find that those made especially for tracking your BBT are easiest to read because they show temps in one-tenth degree increments. Those tiny differences in temperature are important to note, as they reflect important changes in your reproductive hormone levels. A rise of only a few tenths of a degree can indicate that ovulation has occurred.

As the hormones in your body change each cycle, so does your body's cervical fluid (CF). As your body approaches its most fertile time, this fluid (often called non-menstrual 'vaginal discharge') becomes thinner and more slippery. It is sometimes referred to at that time of your cycle as "egg white cervical mucus" (abbreviated EWCM) because of its appearance and texture.

Just as your cervical mucus changes during your cycle, so does the position of your cervix. The cervix is the lowest part of your uterus, extending into your vagina. It acts as a gate between the vagina and uterus, becoming softer, higher in the vaginal passage, more open, and wetter during a woman's fertile time.

There are also secondary signs of approaching fertility that not all women experience, but which can provide additional information if detected. Some of the more common include: midcycle spotting; slight pain or discomfort in the pelvic region; increased sexual feelings; fuller vaginal lips; breast tenderness.

The most important aspect of using FAM to monitor your fertility is to check the three primary indicators daily and record the results. Tracking fertility is all about patterns, and the best way to detect patterns is to keep good daily records for several cycles in a row.