What does this mean?

I usually start a few days than predicted on the app. Been ttc for going on 10months and been regular and consistent every month.

This month tho! I didn’t start till the afternoon of when predicted (Normally I start in the morning)

And it’s really dark and brownish.. unlike all other periods that are bright or dark red.

Took several tests all negative..

Anyone think I could still be in this month??