outbreak similar to whiteheads (male)

I recently began having unprotected sex after being tested with a partner. She is experiencing no symptoms. Despite spending much time looking up and comparing to various common STDs, I have been unable to locate anything that matches my situation. They are temporary and painless, though not numb, whiteheads with no discharge. When the head breaks, it bleeds a small amount and then goes away. They come in groups of 3-5. I have gotten this both on the shaft and, once, the head of the penis. I don't believe these are chancres or warts. Do you think this could simply be exposure to vaginal bacteria, and not an STI at all?