am i pregnant

hi i really need some help so i had unprotected sex on the august 8th i’m on the pill (have been for like 4 months) and he used the pull out method. i start my period wednesday,but i’m having brown discharge could this be from birth control or stress. i just started college and my bf and i broke up and got back together i’m also having to wake up at 5 am to do workouts bc i’m a student athlete so i’ve been having stress. i took a pregnancy test tonight but it came out negative. do you think i’m pregnant?