Brown Discharge

I noticed today that i had brown discharge after sex today, but directly after. like i went and used the bathroom and noticed it. also that little pieces of it was brown in color like the “thick” discharge, but otherwise it wasn’t thick at all it was just on the toilet paper. and not in a direct spot either. this didn’t happen yesterday. but i have unprotected sex but i take birth control around the same time everyday. what do you guys think