Help!! When do I see my BBT drop??

Samantha • Wife💍- Mom 💙 🌈👶🏻💙

I know I ovulated I felt all the symptoms and my OPK’s and BBT all line up but, what I’m wondering if I have not conceived when should I see my BBT start to drop. Does it only drop as soon as AF arrives, days before. I will as of a few hours be 2days from AF. This is my chart. Thanks ladies!