I have a hard lump on my jawbone under my ear, but a little bit closer to my chin. it is on the outside, its hard, lumpy and i cannot move it. i had my wisdom teeth removed a few months ago and i had an infection there where it swelled a lot on the same spot then i got medicine to help it. the infection came back about a month later, and then it left this lump. its not too big, you cannot notice it from looking at me. What is it and what should i do?