Glow keeps moving AF?

Tammy • Married 14yrs, M/C 2002, TTC #1 w/PCOS

I was supposed to get AF on the 27th & Glow keeps asking me if I've started, which I haven't. But I keep trying to delete the period & it keeps moving it back 2days. Why? Can't I just delete it & put it in when it comes?

(Before anyone yells at me to poas) - I have PCOS & I've been regular for a while now but AF being a few days late is(for me) is not a reason to test. I like to wait a week or two.