2 Diff BBT Temps?

StephB • My babies: 💙💝💝

So I woke up at 5:48a & took my temp like usual (I usually temp around 6am so it was 10 min early) & it was 97.99.

I literally just closed my eyes and laid there for 10 min & I took it again just to see/check & it was 97.48.

Which one do I use & why is it so dang different when I literally didn’t move?? 🤦🏼‍♀️