HELP (blood after mastrubation)

So I was super horny today and decided to penetrate myself which I have never done. I'm not a virgin, but I have never stuck something up my vagina to mastrubate. I chose a makeup brush  with plastic around it, washed the plastic and makeup brush  & went at it, when I was done I noticed streaks of blood on the bag. No pain no nothing just blood, what could this be?!! 😩