So a little background...

Currently CD 28. I usually am 27-28 cycle. This cycle it was medicated CD 3-7 I took 2.5mg Letrozole and I was to start progesterone CD 18-30 well.. I had a scan CD 12 my doctor didn’t see any follicles to measure but he did say one was collapsed which means I ovulated. He asked if I felt I “pop” which I did CD 10 and super positive opk CD 11. I stopped taking my progesterone Monday (3 days ago) because I kept getting BFNs and I just wanted my period to come so I could start over. Last cycle I stopped CD 30 and got my period 2 days later. Tuesday I had horrible waves a cramps throughout the day and I was sure that I would start Tuesday or Wednesday (yesterday). I’ve noticed my temp went down just a little bitch then today it spiked 98.54 (mind you I stopped the progesterone) still BFNs and not signs of AF. What could it be? Any advice?