Hello. I Fingered Myself Before Bed Last Night And When

Hello. I fingered myself before bed last night and when I cummed I realized there was blood all over my hand. It was fresh blood. I woke up this morning, tried to check it, the blood has turned brownish, it doesn't flow but it is still there as I dab my vagina with a wet tissue. This is the first time this happens to me and my period is in 13 days. Did I just injure myself without realizing it?