Track your cycles in our FREE app, designed for use with Clearblue Advanced Digital or Digital Ovulation Tests. Identifying your most fertile days is the best place to start. The Clearblue Digital Ovulation Test (Prueba de Ovulación Digital) is more accurate than calendar and temperature methods at predicting the most fertile days[1]. With Clearblue Digital Ovulation Tests, you can accurately identify your 2 most fertile days to maximize your chances of getting pregnant naturally. Each ovulation test kit includes 1 digital reader and 40 individually wrapped ovulation test sticks that track LH (luteinizing hormone), the hormone that surges just before you ovulate. The test sticks have an absorbent tip that can be used directly in your urine stream or dipped into a sample of urine in a clean, dry container. When you see a line with a surge in the result window, you know it's your best time to try for a baby. [1] Study of 101 women in the UK comparing a simple calendar method of conducting a test on LH surge day (2011). Ellis JE., et al. Human Reproduction (2011) 26: i76 (O-191)