Bbt chart thoughts?

Roseanne • As a housewife, I feel that if the kids are still alive when my husband gets home from work, then hey, I've done my job.
Thoughts on my bbt chart? Twice now I input my temp it changes my ovulation day. First it was Dec.16 then changed to Dec.20 and now it's changed to Dec.23. I've had mild cramping on Dec.16 that is still continous. I do have a slight cold and have woken up warm the pass 2 days. Any input would be awesome as my charts have Never looked like this month does. Thanks!