If youre trying to conceive, our 10-Pack of Ovulation Tests represents an excellent value on the highest quality ovulation test strip available. Theyre FDA-approved, highly sensitive (detecting a level of 25 miu/ml LH), and provide a high degree of accuracy in pinpointing your most fertile time of the month. Ovulation Test Strips work by allowing you to detect your monthly "LH Surge" - the dramatic increase in Luteinizing Hormone present in your urine just before you ovulate. Since the best time for fertilization of your egg to occur is within 6-24 hours after you ovulate, correctly gauging your body's cycle is extremely helpful in increasing your chances of becoming pregnant.