need help on my bbt.

Nikki • Mommy of 1 and currently expecting #2 in February 2021. 🥰
Can someone tell me what's going on with my bbt this month? My bbt for last few months has been consistent. I've used OPK and just finished ovulating. My temp usually goes up after O but this month is like zig zag. And I do not have cover line
Below are my last 2 months.