blood is coming out of me…

okay so i’m only 17 so things like this freak me the hell out. i just went to the bathroom and look at my panties and saw what seemed to be brown blood in them. i went to wipe myself and there was blood down there. i would think it was just my period starting but it ended two weeks ago and my fertile window ended just yesterday. i don’t think it’s my period starting early especially since i’ve been sick for the past week and rlly haven’t done anything sexual (like masterbation which as a growing girl i feel is normal to do) lately. tomorrow i’m going to dc and will be out all day and i’m scared it’s something more… if there’s anyone who thinks they know what could be happening without me looking like a dumb child it would be helpful thank you!