We recommend using the test in the morning on cycle days 3, 4 and 5. Count from day 1, which is the first day of full bleeding (heavy flow) from your period. If you start your full bleed after 5 p.m., you can consider the next day your day 1. If you are past cycle day 5, then you will need to wait until the next cycle. And if you don’t have regular cycles, go see your doctor for a workup.