Hello, I am a 21 year old I have a small lump on the base of my shaft, it’s not noticeable much but when fully erect it’s noticeable. Half way through any pleasure this semi hard bit on my penile begins the be sore. Is this serious and should I get this checked out, I have had this “lump” in question for about 2 years now, I have had a test for STI’s and it came back negative.