Clearblue Digital Ovulation Test with Dual Hormone Indicator kit, 10 tests is the only typical test to identify 4 or more fertile days when you have the best chances to get pregnant naturally. Accurately tracking 2 key fertility hormones, estrogen & luteinising hormone (LH), the test identifies 2 Peak fertility days, like all other ovulation tests, but also additional High fertility days before you have more opportunities to get pregnant.