Tracking late periods

Myranda • Happily married 3yrs | 👶🏼 #1 in 2018 💕

Can someone help me log when my period was supposed to have started? I keep moving it cuz I’m late but now I’m wondering when I was supposed to have started. I can’t remember if it was 12/13 or 12/14. Either way I’m 4-5days late!! Am I missing a feature on the app that can help me?