About 4 days ago I engaged in oral sex. Now when I go to the bathroom and pee, the very tip of my penis stings as the urine is passing through. Also it stings for a minute or two after, no pain in any other area, no visual abnormalities of any kind.....going to get checked for stds, but perhaps it is possible that the tip is bruised? I feel like it is bruised, say if I squeeze my tip gently it begins to ache and sting....but I have no pain unless I am touching it like that or urinating.