Refer to your usual cycle length, i.e. the number of days between the first day of your last period and the first day of your next period (period tracking apps are a great way to get this information).
Based on this number, refer to the table in the instructions to determine the best day to test. For example, if the first day of your last period was the 1st and your cycle is usually 28 days long, you should start testing on the 12th. See this article for more information!
At the time of testing (we recommend you do it between 10am and 8pm, not with the first morning's urine), remove the purple cap and urinate on the paper towel for 5 seconds or dip the test into a urine bottle. If you can, try not to drink too much liquid or pee a few hours before the test as this will dilute the test results.