ok, so on the bottom right side of the shaft of my penis i have what appears to be a pimple. there is no pain, however i have popped it 3 times now over the course of the day and the whitehead keeps coming back. there is now a rash on my penis shaft, receding just below the circumcision scar. i had sex the previous day but my girlfriend and i are both the only sexual partners in eachother's lives. please help