I had the same problem a few days ago. When it first happened, I freaked out, but now I know that for me the problem is constipation. When you squat too hard, you can form a tear in that area and some blood comes out.
When it occurs, I drink lots of water and eat lots of fruit like oranges etc and that helps.
But that is the problem for me, and likely for you too. But, do get it checked out!