I need some BBT help!

So I’ve been temping and it’s been staying pretty regular since I’ve become pregnant. Last night I slept with the ceiling fan on high and when I woke up to pee I took my temp before getting out of bed. Now I am also a mouth breather and when I woke up my mouth was so dry I could barely shut it to temp. My temp dropped.18 degrees!! I went back to sleep and slept for almost 4 more hours. When I woke back up I tempted again and it was actually a little higher than my before tempts.......

Idk what to do or think now?!?? I’m scared I’m goin to miscarry again!