Teagz, you really need to know your temps throughout your cycle to tell, but 37.2 is high, so yes, there is a good chance you O'ed on CD13. You can join free for basic membership on FF. You may already know, but there are do's and don't's with temping, so worth understanding them so you track as accurately as possible, if that is what you want to do. Good-luck with it. It is interesting