Ok guys, first time here and I am worried about something,

The past couple of days I have had a sharp rubbing pain between my sac and my anus, and erlier, when I went to the toilet, There was a bit of blood on the tissue paper, this has never happened before. After feeling around it feels swollen, but longways, if you get what I mean, Could it be a scratch that has swelled a bit? it is longways like a scratch would be. And Iam 17 years old.