Clearblue Ovulation Tests detect the Luteinising Hormone (LH) surge which occurs approximately 24-36 hours prior to ovulation. This is how they help you pinpoint the 2 best days of your cycle to conceive - the day before ovulation and the day of ovulation itself. So, if you make love on these 2 days, you’ll be giving yourself the best chance of becoming pregnant.
The Clearblue Fertility Monitor can identify more fertile days each cycle, both High and Peak Fertility days. It not only detects the LH surge and pinpoints your 2 Peak Fertility days, but also identifies typically up to 5 additional fertile days when you may conceive (High Fertility days) by detecting the rise in estrogen which occurs immediately before this LH surge. As your partner’s sperm can survive in your body for several days, making love on those days can also result in pregnancy. It also gives you personal information, telling you when you need to test and when the end of your cycle is.