Being a past victim of boils, I honestly think that the bump you are describing is an abscess. Have you been to a dentist recently? If not, then it might be time that you go and have a dental checkup. And the type of abscess I'm talking about has nothing to do with boils or staph. It's an infection you get above/below your teeth when there is a problem in your gums. I had a tooth that needed a root canal, that kept abscessing on me. It went away, then came back several times but it was always right above that tooth. Had the root canal, and it's been good ever since.

My mom had a tooth abscess when she was younger and they told her that had she waited longer, it could have ruptured and given her blood poisoning. Definately not something to mess around with. Go get it checked, it will give you peace of mind to know what it is. Good luck.