Are you putting chapstick or anything on your lips? Otherwise try changing toothpaste.

If you popped it and it came back it means you didn't fully extract all the puss from it, and it got reinfected. It's better to leave it alone and see if it goes away on its own. If it's bothering you a lot, you can try applying a hot compress/ cotton pad on it until it pops, then reapply the heat when the bleeding stops to prevent it from forming again.