I Have A Bump On The Side Of My Penis

I have a bump on the side of my penis that continues to grow larger. It looks about like a very large pimpe at this point. I'm sure it isn't an std as I've had the same partner for over a year and have been tested before and during this partner as well as she. This bump has a small white spot on it and today has developed a small purple looking spot in the middle along with the 2 white spots. It is raised off the side quite a bit. I have a picture of there's any way I can post it