Help me ID my ovulation?

Hi!  I'm new to the whole BBT 'world' and I am hoping someone here could help me ID when my ovulation occurred?  According to glow my peak fertility day was Sept. 7th... However I am pretty sure I ovulated on the 3rd.  I do not check my CM, I only take note when it is very noticeable.  Any advice is greatly appreciated!!!  😊