It could be an ingrown hair or a clogged pore.
I have a white bump below my lower lip. Do you know what this might be? It's soft and hard at the same time.
I had pimples that went on my lower lip now sometimes them can be cold sores too or ingrown hair, try some medicated lip balm that will help.
I have one right now too and my mom said it's just a pimple. Put on some Clean & Clear lip stuff. It REALLY helps. Here's a picture of my profile pic:
