Help! Confused with bbt..

This is my first time accurately charting bbt (I know I started half was through cycle but we were supposed to TTC this month). The last time I started to chart bbt, I was in the 98 range but was already pregnant and didn’t know. This is my chart for this month.. I am 17DPO, period is currently 4 days late and I’ve had 3 negative pregnancy tests (2 frer bfn at 9DPO and 10DPO and a bfn at the clinic 12DPO (my first pregnancy I got my bfp at 10DPO).

I’m so confused and annoyed! This was the month we could actively start trying again after healing from a procedure and now af is no where to be seen and my temps are all over the place! 😩