I too would say that you o'd on CD13.
Your chart around o time looks similar to my last in which I concieved. FF was trying to say that I o'd later than I did as I had 3 days at the same temp that were slightly higher. I had to change my o date as FF was wrong, I know my date was right as I got a BFP at 10DPO.
My chart is below if you would like to see:
22f270 Ovulation Charts
I hope I made some sort of sense.
Your chart looks great by the way. When will you be testing?