When did I Ovulate? PLEASE HELP!

Hi, I've been TTC for about 5 months, and I still get confused about when I'm ovulating! Can anyone help? I would REALLY appreciate the help! Last Friday I got a positive opk test around 8am. Then a negative opk test Saturday around 8am, with a small spike in my bbt. From what I've read (positive opk showing LH surge occurs 12-24 hours before ovulation, and spike in bbt occurs right after ovulation), that would mean I probably ovulated late Friday night into early Saturday morning. I just don't know which date to count as my ovulation day! Does anyone agree, or think otherwise, or have advice on which day to count as ovulation?? Thanks in advance for any help or advice!