I’m bleeding !!!

I bleed every time i masturbate. I’ve only had sex once and I’m on birth control. I’m not on my period and it’s been happening ever since i had sex that one time. I started birth control right after and i got my period a couple days later so Ik this isn’t a period. Idk if it’s bc he was big and the sex was kinda rough or bc of the birth control but i bleed every time i masturbate. Its only clit stimulation so I’m not penetrating myself. After i climax i feel a sploosh feeling and out comes dark red blood i don’t continue to bleed after words it’s jus light spotting and it’s over. What’s wrong?