when should I take a test?

Aimee
My apps both say I'm due to test on 25th but AF isn't due until 28th. Does that sound right to anyone? I have a really hard time <a href="https://play.google.com/store/apps/details?id=com.glow.android">tracking ovulation</a> even with tests. Maybe all my guess work adjusted the cycle? When should I test?