When I m done peeing, my bladder hurts really bad, like a sharp pain. and when it hurts a little bit of blood will come out. the First day I felt this I had to pee like every half hour, but barley anything would come out but if I hold to where I really have to go. I pee a normal amount and it wont hurt and no blood will come out. So it s the less I pee, the more it hurts and the more blood. I m Female, 17, 5 3 129lbs. what could this be?