Ovulation lh peak, no period, no positive pregnancy test

Wondering if anyone has ever had this happen. I got off birth control pill 4 months ago and after the first month my cycles were pretty normal (33 days). I have been testing ovulation with lh strips and my last cycle got a positive at the expected window. We BD in the window and then my period was late.

What’s weird is all my HCG tests are negative. Its now CD40 (23dpo) with no + test and no real period. I had light spotting on CD36 and CD37 (17, 18dpo).

Has anyone had this happen or have ideas of what it could mean? So confused. My doc says ovulation can skip due to stress etc and not to worry unless it’s been 60 days, but the strips said I ovulated?