Recently after hanging I noticed a reddish bump, oval in shape and no larger than 1/4”x1/8” on the underside of my penis about 1/3 of the way up my shaft. It is not painful nor does it feel really hard, rather you can pick up the skin and sort of roll it between your fingers and it gives a little, almost as if it were filled with some sort of fluid. The skin on top is pinkish/reddish and smoother than the rest of my penis. Could this be a thrombosed vein? It doesn’t seem to be lying on or near any veins that I can see.