Pinpointing ovulation help

Fran

I am desperately trying to pinpoint my ovulation date after stopping Cerazette on June 23.

I had nothing until July 23 when I clearly had egg white CM. I thought I ovulated and the opk didn’t pick it up.. Then cramps starting a couple of days later and finally opk positive on July 27. I had cramps since… I am really confused on what date I should consider🤷‍♀️any clue?