Fingering

So I’ve had sex before, with the same guy(my boyfriend.) When we last hung out he fingered me & when he went down to eat me out his hands were full of blood. He stopped because he was worried about me. I went to clean everything up & i soon stopped bleeding, maybe a 1/2 hour later. It wasn’t period, so what could it have been?? Help! He was super sweet tbh. (He was concerned/worried about how I was doing & kept making sure I was alright the rest of the night.)