Can i get a l infection from a poop stain in my underwear?

This is gross, but today I noticed there was a light brown mark in my underwear along with my normal discharge, which has always been dark, and sometimes brownish. I can't tell if it's discharge or a poop stain. I didn't poop today, so I don't know why it would be a poop stain, but if it was, could I get BV from this?