I noticed a knot-like thing under my skin. It is about the size/shape of half a piece of rice. It is slightly painful when i touch it. It just showed up today. I think it has something to do with a blood vessel or something. I think it may be swelled or something. It is on the underside of the penis about one mm lateral to the frenulum line. It feels almost as if it was a pimple or somehting but under the skin. I can't figure it out, i am a bit worried as to what it is. The skin is raised a slight bit where it is at. I tried taking a picture but I really cant capture it in a pic.