Clearblue is the only test that detects the rise in 2 fertility hormones, estrogens & luteinising hormone (LH) before ovulation. Make love on high & peak fertility days to maximise your chances of getting pregnant naturally. Accurate The simple urine tests are proven to be over 99% accurate at detecting the LH surge. They are two times more accurate than calendar methods. Study of 101 women in the UK, comparing a simple calendar method to likelihood of conducting a test on LH surge day (2011). Clear digital results In a study, the clear digital results were the easiest to read & clearer than line tests. Study of 72 women in the UK reading ovulation tests typical of normal cycle results (2010).