If your usual cycle length is 24 days or more, start testing on Day 9 of your menstrual cycle. To work out when Day 9 is you should count the day your period starts as Day 1, and continue counting through to Day 9. This is the day you should start testing.
If your usual cycle length is less than 24 days you can use this Test, but you should start testing on Day 5 of your cycle. To work out when Day 5 is you should count the day your period starts as Day 1, and continue counting through to Day 5. This is the day you should start testing. If your cycle length varies, but has been less than 24 days in the last 3 cycles you should start testing on Day 5.
You can test any time of the day, but it should be at about the same time each day (many women find it most convenient first thing in the morning). It is important that you have not urinated for at least 4 hours before testing, and you should avoid excessive fluid intake before testing.