How many dpo am i?

Kristin • Been married 8 yrs, actively TTC for 6 yrs. I have PCOS & insulin resistance and never ovulate. My cycles are 100+ days. We just finished our fourth round of clomid.
Ok, everyone thinks my opk on Friday was positive. I'll call the dr on Monday for blood draw to see if I really did, 4th round of clomid. But if my Friday opk was positive, what day do I assume I ovulated to know how many dpo I am now?