Q. How can I tell if I'm ovulating?
A. Charting your basal body temperature is the best way to find out if you’re ovulating. This temperature is normally biphasic, meaning that a woman’s temperature during the first two weeks of her cycle is lower, then the temperature rises and stays up for the second half. The problem is that this method doesn’t predict ovulation, it just shows that ovulation has occurred. So it’s not really helpful for people who are looking to pinpoint the most promising days to have sex for the best chance of conceiving. Once ovulation has already occurred it’s generally too late for conception to take place. Basal body temperature charting is most helpful for people who just want to determine that they are actually ovulating.
For couples who are really looking for help pinpointing their most fertile days in order to time sexual intercourse, a better choice would be an ovulation predictor. Most of these tests work by detecting an increase in luteinizing hormone (LH) in the urine. This “LH surge” generally means that ovulation will occur in the next 24 to 48 hours. The kits come with good instructions, and are about 90 percent accurate.
There are some women who will have difficulty using these kits. Women with PCOS (polycystic ovarian syndrome), for example, may always get positive results because of high levels of LH in their bodies.
Not all ovulation-tracking devices test urine; some check the chloride levels in sweat or the estrogen levels in saliva. Ask your doctor and do some research on your own to find the kit that will work best for you.