I had sex with my girlfriend who was a virgin ,now I have these little tiny bumps under my penis head they don't itch or burn ,I haven't had a discharge or a burning sensation when I pee the bumps are just there ,can you help me

There penile cold sores, basically tiny blisters that appear under he skin, they eventually go away if untreated after about 3 weeks. Your doctor will probably prescribe an ointment that will clear them up in a week. They are quite common.