Am i damaged?(Not breakfast reading!)

Me and the boyf had a major sex session Sat night and neither of us could get enough, this went on for a couple of hours and there were a few beers and lines involved.

Anyway during some foreplay he managed to get most of his hand inside me and i loved it, it stayed there until i orgasamed but when he withdrew his hand it was covered in blood :O

I havent bled since that but have really bad period like cramps and my back is v sore too. As I'm on the injection I do not get periods and havent had one in nearly a year which is y the blood was such a shock. Could i be damaged inside, I have a fear of internal examinatons since my first baby so only will go to the doc as a last resort.

Has anyone expierenced anything like this?????