dark brown spotting

Hailey
So I've been on my period for 8 days!!! Usually my periods are only 5-6 days long & yesterday I thought AF finally left but I have dark brown spotting & im confused.. has this happened to anyone, also would like to note my boyfriend & I BD 2 days ago, not sure if that would have to do with it?? Is pregancy a possibility that early off your period?