Should I use BBTs and OPKs when trying to get pregnant?

There is no need to use BBTs or OPKs if you have regular cycles and no diagnosed infertility problems. That’s because BBTs and OPKs cannot increase your chances of getting pregnant if you ovulate regularly.

Basal body temperature charting (BBT) and OPKs (ovulation predictor kits) can provide valuable information for women with infertility. Both are methods to determine if and when a woman is ovulating (releasing an egg).

Basal body temperature charting relies on the fact that your body temperature rises slightly around the time of ovulation and for the rest of the cycle. You need to take your temperature with a sensitive and accurate thermometer as soon as you get up each day. Then you record your temperatures on a chart. Your chart will show a rise in body temperature when you ovulate.

Ovulation predictor kits detect the luteinizing hormone (LH) in your urine. Levels of LH rise before ovulation. You can test your urine on the days that you suspect that ovulation is approaching (or every day if you don’t know when you ovulate). When the OPK result is positive, ovulation will occur in the next day or so.

BBT charting and OPKs are very helpful for women with very irregular periods who have no idea when they will ovulate next. They are also helpful for women who are taking medication that stimulates ovulation.

As mentioned above, BBTs and OPKs offer no benefit if you have regular menstrual cycles. That’s because you are almost certainly ovulating each month, generally 14 days before you expect your next period. So BBTs and OPKs provide no additional information for you.

Furthermore, there are many reasons that you might not conceive in a given month, but timing is not one of them. Sperm can live in your body for many days after intercourse, so if you have intercourse sometime in the days before ovulation, you can get pregnant.

So why don’t you get pregnant every month that you try? Human reproduction is a rather wasteful process. Women are born with millions of eggs they will never use. Men make billions of sperm every week. Sometimes the egg is abnormal. Sometimes the sperm is abnormal. Sometimes the egg and sperm don’t combine properly, or lead to an abnormal embryo. Sometimes the fertilized egg does not implant properly in the uterus and gets washed out with the next period.

A woman who is ovulating regularly cannot increase her chances of getting pregnant by using BBTs or OPKs or by any other method.