[Kumagoro]

Like the others have said, it could be a cut or scratch from his fingernails. But even though you've been having sex, it is still possible that your hymen was still intact all that time. That's something only you can know, of course, but sometimes a hymen simply stretches during sex or fingering, and takes longer than you might expect to properly tear. You might want to go and see a gynocologist as they will be able to tell you if it's broken and identify why you're bleeding all of a sudden.

Take care