WHY AM I BLEEDING

 First let's start off with I am 20 years old and have always had normal on time periods, I'm not suppose to start for another 6 days.. a few days ago I noticed I had a blood spot in my underwear but when I wiped nothing at all, lastnight we were getting ready to leave Chicago stopped at a gas station I ran in and went pee, we had a 3 hour drive home.. I stopped at my moms which was 2 hours away and had blood again a little more this time but once again when I wiped nothing.. so didn't worry about it.. got back home and still nothing... why am I bleeding???