brown discharge???

so me and my boyfriend had sex about 2 weeks ago and i forgot my pill at my apartment, but had been on time with them at least a week before. we did stuff in the morning with nothing but i had been on time with my pills in the past. i’ve been on time with my pills ever since but for some reason today i had a brown like discharge, very very slight... nothing when i wiped, just on my underwear. could this just be an early sign of my period, i’ve been going through a lot of stress and we are having drastic weather change in my town?? or should i get a test to be sure?? i’m supposed to get my period tuesday or wednesday of this upcoming week. i have no pregnancy symptoms but i know brown discharge can be also implant bleeding.. i just really want some options and advice on what i should do.