Please help! i don't know what this is!?

Yesterday I noticed a bump on the middle part of my lower lip. It is completely located on my lip, and not just on the edge of it. It is a raised bump with a somewhat white center and is painful to the touch and has a tingling sensation. I did some research and found that is seems somewhat like a cold sore, but over the course of the day I noticed three more similar bumps appear, and seeing as how I've never had a cold sore before, I didn't know if this was a common thing. I now have four bumps in total, two on my upper lip and two on my lower lip.. each in a different place. If it is a cold sore, the only possible place that that I could have gotten it from is my boyfriend; however, he has never had a cold sore (but his mom has), so I don't know how likely this would be. Because of all of this I am really starting to worry now. Could this maybe be something other than a cold sore.. like an STI resulting from giving oral sex? I have done this with my boyfriend, but he doesn't have any known STIs and has never had any kind of problems. Please, any advice or information you could give me would really help!