ovulation/DPO HELP PLEASE!!!

Jennifer
Ok so every month I ovulate between cd13, 14, or 15. I got my positive opk on cd12 this month and ff thinks I ovulated that day (I got the positive at night) which I don't think is correct. My best guess is cd14 is when I ovulated. What do you guys think? Not having my normal spotting before af (usually that happens on luteal day 10) what do you think?