Clearblue Digital Ovulation Test is one of easiest to read ovulation tests on the market. Simply insert the test stick in the test holder and the test ready  symbol will appear on the display window. Hold the absorbent sampler in the urine stream for 5 to 7 seconds. Within 3 minutes the test will show a result. A blank circle symbolises a negative result or a smiley face indicates a positive result. This test has a 99% accuracy rate. Clearblue Digital Ovulation Test works by detecting an increase (surge) in the hormone called Luteinising Hormone (LH) in your urine. This LH surge occurs prior to the release of an egg from your ovaries - a process known as ovulaton. You are at your most fertile on the day your LH surge is detected and the day after. Clearblue Digital Ovulation Test is not intended for contraceptive use and is not suitable if you have recently been pregnant, reached menopause, have polycystic ovary syndrome or are taking certain fertility drugs. Clearblue Digital Ovulation test can be used if you are taking clomiphene citrate.