Bumps under the skin of penis head

After taking going through three STD testing, my doctor said that I have no herpes or any other STDs. I showed him that I had a couple of bumps under the head of my penis (not visible to my view unless I twist my penis around to see it...get the picture), and he said it is skin variation. However, I sometimes get an itch feeling during the day in the area where they bumps are present. Could this be an early sign of genitial herpes or warts, even though my tests came back negative three times?