Over-the-counter ovulation tests for ovulation prediction are dominated by urine-based tests. They check for spikes in the woman’s levels of luteinizing hormone, or LH.

The luteinizing hormone is always present in your urine, and it increases 24-48 hours prior to ovulation.

When used correctly, LH tests are around 99% accurate. 

However, these tests cannot confirm whether ovulation actually occurs a day or two later. 

Cases when positive ovulation tests may be misleading:

• Some women may have a surge in the LH hormone without releasing an egg. This condition is known as Luteinized Unruptured Follicle Syndrome (LUFS).

• Other women may experience false small peaks in the LH hormone before it fully peaks, commonly seen in women with polycystic ovarian syndrome (PCOS).

Keep logging your data with the MIA app every day to learn more about your body.