I think you may have O'd on CD15. The earlier-than-normal temp could be preventing CH's because your temp tends to rise as you continue to sleep (so temping later you usually will get a higher reading, and earlier you can get a lower reading) so it may not be showing as big of a temp shift as what may have occurred. Does that make sense?
I definitely see a progressive rise too, and if you want to click on my BFP chart in my sig, you can see that most of my cycles have a slow rise after O.