BBT all over the place.

Dianna • We are trying for our first child together. I am lucky to be a step mom, but we want one together as well.
My BBT is always all over the place. Ranges from 96.80-97.9 on any given day. I know it's supposed to go up slightly while ovulating, but how slight is slightly? I don't know if I will be able to tell when I'm ovulating due to my BBT being so crazy.