Elevated BBT

Hi all. I've been chatting my bbt from the beginning and this cycle it has been all over the place. I live in MN and we are going through our drastic rise and fall of daily temperatures. I am wondering if this could possibly affect my bbt. The last couple days I was mid 98° and today it dropped to 97.7 (my normal bbt). I will add that when I sleep out from under the covers my bbt seems to be lower, from the ceiling fan maybe? PS: I'm three days late. Thanks!