If you are trying to get pregnant, your OB-GYN can talk to you about ovulation predictor kits that include a variety of tests for determining when you are the most fertile. These tests work by detecting a sudden rise in the luteinizing hormone (LH), which is something that happens within one or two days of ovulation. However, they are only accurate when performed at the right time during a woman’s menstrual cycle. Approximately 36 hours after an LH surge has been detected is the most likely time for an egg to be successfully fertilized. At-home ovulation tests include both “test strips,” which are strips that you place in a container filled with the prospective mother’s urine, and “midstream tests,” which are similar to pregnancy tests where you hold a strip in the urine stream – each are considered equally reliable when used as directed.