Alright, so yesterday I was at a friend's house and I felt some liquid come out of my vagina and I…

Alright, so yesterday I was at a friend's house and I felt some liquid come out of my vagina and I go to the bathroom and there's some brownish colored blood in my panties. I put on a pad and barely bled at all and it's still brownish in color. But I haven't bled anymore and if it was my period it would be a pretty heavy flow. My period isn't due for another week. So do any of you ladies know what it could be?