The most common bumps you can get from piercings look like these.
There are several things that can cause these annoying little things. Poor fitting jewelry, playing with your piercing too much, giving it a good pull etc.
So how to fix it. In my experience there is only one way to deal with this problem and that is with wet heat.
So take a wet hot cloth, as hot as you can stand it and apply it to the area. Leave it on until it cools. Then follow it up with some sea salts to dry it out. You need to do this 2 - 3 times a day until it's gone. Some are gone within a week and others can be more stubborn taking a couple of weeks.