Bleeding when fingered?!

Hey ladies so I need help. Every time my boyfriend fingers me hard or even at all for the last 2 weeks I've bled afterwards and during and we don't know why?? Last time was just before my period so we thought it was that but now it's happened again and my period finished 5 days ago. I've gotten him to cut his fingernails shorter now because I did realise he'd accidentally cut a little but on the outside but I'm just feeling really over sensitive. Help :(