Ovulation tests are tools used to determine the most fertile days in a woman's menstrual cycle. They work by detecting the surge of the hormone luteinizing hormone (LH) that occurs just before ovulation. By identifying this surge, women can better plan for conception or understand their cycle. These tests come in various forms, including urine test strips and digital monitors. Users typically test their urine daily during the fertile window, which is usually a few days before ovulation. Accurate timing can increase the chances of pregnancy for those trying to conceive.