it is very wierd. i can't figure it out. first glance though, i thought maybe you o-ed on cd17. cm seems to say earlier though, like ff does. you mentioned your pre o temps were high this time - maybe it's something environmental (new winter blanky) or the cold you were dealing with. if those were magically lower, then would it make sense that o is really at 15?
i actually think both of us should go have ultrasounds done and then get trigger shots when it's time to o, to make sure stuff's happening the way it should. i have no faith in my body right now.