Bumps on penis shaft

Recently, I noticed a few bumps on the shaft of my penis that looked like pimples. I trim my pubic hair occasionally, and had trimmed a few days before I noticed the bumps. I also had had sex (I have had sex with the same woman for the last year) within the previous few days of noticing them. . We used lube, and I'm wondering if the combination of shortened pubic hairs and the lube may have been a factor in the development of the bumps. Looking at them now, about 2 weeks later, they aren't getting any better; in fact, I think they look worse, and might have spread a little. They have also hardened a bit. They do not cause pain, do not itch, do not burn, or any other discomfort aside from being unsightly. There are about 8 total, and like I said, look like either pimples or possibly small warts. I'm wondering if you can tell me what I might be experiencing?