Period

How do you tell glow you're not on your period? Seriously, I recorded no period on the log for three days and it's still saying I'm on cycle day 3. Of course it said I was supposed to start the 12th and changed it to the 18th. But now it won't go. So I'm either almost a week late or ony three days late. Glow is confusing. And my other app, ovia is telling me I should take a test in 6 days.