A woman can only become pregnant on a few days of her cycle. If you want to have a child, you should have intercourse on those days. With the Clearblue Digital Ovulation Test, you can calculate your fertile days and maximize your chances of natural conception. The test identifies your two most fertile days by measuring the key fertility hormone – luteinizing hormone (LH). The Clearblue Digital Ovulation Test is not only more reliable than the calendar or temperature measurement methods, but it is also particularly user-friendly – the result is displayed on a digital screen, eliminating the need to interpret lines.