Okay, REALLY CONFUSED....help!!

So, my bbt chart is kind of wonky, always has been, but that is my 'norm.' I am 13 dpo, AF due tomorrow, and temps had been heading downward as if AF was, in fact, going to rear her ugly head. This morning, though, my temp skyrocketed from 96.95 (yesterday) to 98!! Is this a promising sign? I have taken a few tests but none in past two days because I was getting BFNs so decided was just waiting for AF cause I was tired of the disappointment. What does everyone think???