Dip in BBT relates to MC?

Tera
Hi all
​So I have been charting my bbt for the past 6 weeks. It's been elevated since ovulation and I'm just 5 weeks.
​Today my bbt took a plunge. At 2:45 AM after 3 hours of sleep. It was -1.1 degrees below my cover line. (I don't know why I woke up...nerves.)
​Eek.  Now this can neen I'm about to MC. But, can bbt be inaccurate bc I took it at 2:45 am instead of the usual 7;00 AM?
​I had some brown spotting yesterday so I'm on edge.
​Fingers crossed for all of us.