Basically I have a lump / bump on my penis. It is below the shaft on the left side of my penis and is more pronounced when erect. It in behind the skin of my penis and is almost like a hard pea in shape. I have had this from what I remember for about 4 years and only recently I have started to worry about it. I am 15 years of age and have never had sex so obviously no chance of STI's etc. I am also circumcised. Basically I would just like to know if anyone had ideas of what it could be and what I should do as I would rather check online to see what it to identify it.