Could I be pregnant?

My period was on August 25, had unprotected sex on Friday September 1. My boyfriend did finish inside me.

Today I noticed brown discharge when I wipe with a tint of light pink blood, part of me thinks this is implantation bleeding.

I am not having any sort of cramping, just the light bleeding but it’s not bright red like my period it is brown like “literally”.

Could this mean I’m pregnant?

I mean i’ve never bled or spotted after my period ended up until I get my next period.

My next period isn’t suppose to come until September 17-20.