His fingernails may have scraped you.

Are you experiencing pain?

this happened to me the other night :s my boyfriend fingerd me but i was sat up when he did it i think he scrated me but there was quite alot of blood but it soon stopped :s i thought it might have been an erosion of the cervix as it is common in women and ive had that experience before but its nothign serious, if this happens regular or bleeding inbetween periods then that'd be when to go see a doctor, other wise don't be worrying