Pain during sex ..

I was having sex and was in the doggy position. It felt like the tip of his penis was hitting something inside me and it was kinda painful where we had to switch positions. When the condom came off (we always inspect it to make sure there are no tears) we saw that it had like a drop of blood on the tip of the condom. It had dried out but it was just a single drop... What in the world could that mean?