AF coming or Implantation dip??? 🤔🤔🤔

Hello ladies, this is my first medicated cycle with letrozole 2.5 mg. I got my trigger 5000 iu on Feb 25 Cd12. On cd 14 scan, I had follicle of 23mm but not ruptured. So doc told me to wait for couple of days. Usually I Ovulate on cd17 on my own. I hope trigger didn't work for and I O'd on Cd16 as per the temps.. Am on 10 dpo 13 dpt today. I had drastic dip in my temp that touched my coverline. Is my AF due.. I have very regular cycle of 29 days and my AF is due on Mar 15.. Pls help....