Many women have concerns about their ovulation or want to make sure that they are timing their sexual activity properly in order to get pregnant. Good news – relax! Aside from hormones such as birth control pills, there is no way that women get their cycle monthly aside from ovulation. So if you are having periods every 21 to 35 days with reasonable regularity, the question is not how to tell if you are ovulating, but rather, when.
Ovulation happens about 14 days before the next menstrual period, with some variability (range is from 10 to 16 days). Therefore, the easiest way to figure out your ovulation date is count backward by approximately 14 days from your next expected period. Example: if you have 30 day cycles, ovulation generally happens around day 16. It gets more tricky if the cycles are not very regular, and this is where more complex methods of ovulation detection may be especially helpful.
Many hormonal changes occur during a normal menstrual cycle. Key events in the cycle are rising estrogen made by the developing egg follicle; a dramatic surge in LH (luteinizing hormone) 24 to 36 hours prior to ovulation; and a large increase in progesterone coming from the egg follicle which recently ovulated, for the support of the pregnancy.
Home ovulation methods are based on the detection of these hormone products in urine or saliva, or the changes in other body fluids such as cervical mucus in the vagina. The simplest and least expensive method is the detection of the LH surge in urine. Many women refer to this as “pee on a stick” although there are different ways of performing the test depending on the kit. Many kits are available in the drug stores. For most women, this is adequate and accurate. Ovulation occurs approximately 12 to 24 hours after the detection of the LH surge in the urine. By the way, the LH rises slightly before the full surge so some women may detect a slight increase prior to a full surge.
When you perform an internet search of ovulation detection, you will encounter many more expensive and complex devices which measure estrogen in saliva, changes in impedance in vaginal secretions, or help keep track of your results month to month for easy access. If your main goal is to make sure that you are trying at the right time, these may not be necessary. But if you are technically minded, these can be very helpful.
What is the right time to have sex to get pregnant? Turns out that the best time is one or two days before or just after your ovulation (within 24 hours). More than a day after ovulation, there were no pregnancies noted in a large study. But a woman can get pregnant with one act of intercourse many days (up to 7 days) prior to ovulation, but at a much lower frequency. So, make sure that you have tried within a day of the detection of the surge with the urine LH. No harm in trying earlier. Also, some women have a hard time seeing the color change before ovulation, so you don’t want to wait until the test is positive in case it isn’t accurate for a particular month.
In my practice, if a couple is typically having sex 3 or 4 times a week, and the woman has regular cycles, I don’t see a big benefit in ovulation testing. However, some women find it reassuring regarding their timing and the fact that they have a good ovulation.
If the menstrual cycles are not regular, ovulation detection is much more difficult, and chance of pregnancy, even with properly timed intercourse, is much lower. Best to see a fertility specialist to get some help.
©Copyright Patricia McShane, M.D.
