Fertile time on Glow seems off?

I have been off any kinds of birth control for 9 months now. I would say casually TTC, intimate 2-3 times during my fertile period. I used to track my CM very consistently but since getting married last September & beginning to have sex regularly it seems my CM is not as readable & harder to track.

My question is, if my CM is harder to track, but I always seem to still have CM outside Glows predicted fertile window, is it possible I'm not really aware of my most fertile times?? I was just at the doctor Wednesday & she mentioned the third week is the best time to get pregnant. My calendar always says the 1-2 week. HELP!!