Once you have decided to have a baby you may want to know how to give yourself the best chance of conceiving. This is where Clearblue can help, it is an easy and straightforward test that lets you know the best 2 days to conceive your baby. You can only become pregnant on a few days each month. To increase your chances of getting pregnant you should make love on the days leading up to and including ovulation - this is when an egg is released and consequently when you are most fertile. Ovulation is controlled by your hormones, in particular one called luteinising hormone (LH), which can be measured in your urine. Clearplan detects a rise or surge in LH that occurs before ovulation, letting you know that now is the time to make the most of your fertility. 99% accurate. Clearblue is the most effective ovulation kit because with 7 sticks, more women will detect their LH surge than with any 5 test kit.