My gurlfriend had irration from her pad she was wearing then she noticed she had bumps not on her vagina but under anal region where her pad was touching... we had sex a couple of days after she got off her period.a couple days after we did I had small bumps on the head and shaft of ma penis.hers went away.. and I'm worried

It sounds like it could possibly be genital warts although it could be something much less serious such as pimples.
I would go and see your doctor to get an accurate diagnosis.