Colds can do weird things to charts... they can give you high temps and/or low temps. I had the same thing with my chart when I had a toothache... FF didn't know what to do so it said I had ovulated and then changed its mind a few weeks later (I have VERY long cycles). I would say that FF may correct itself once it gets further info from the next few days.

Based on the cold info I would say that CD12 is not when you ovulated but the fertile CM around CD15-CD17 may be when you ovulated. The negative OPK is also going to confuse FF.

Sorry I haven't really been much help... I hope that with a few more temps FF sorts itself out.