What is going on!?

Please help! These are my last 3 months of BBT Analysts (including this month). I can see a clear spike in Oct and Nov but Dec is all jacked up and this is the month we started ttc. I have no idea where or when I ovulated. And my temp isn’t staying high after ovulation like it normally would be right now. The three last days in a row on the December chart are 97.18’s..I don’t understand needing some advice.