What Causes Lumps On The Penis Shaft?

dear doc i have a pimple like bump on my upper shaft, that indeed poped just like a white head, is it possible this is a early stage of genital warts, i have been checked for everything else, and also may note i have white bumps all on the shaft since forever, i read these are fordyce spots and docter said there normal but i didnt have this one imbulged pimple like bump at time, also note i got this the morning after i masterbated. please reply and help