I have a small round ball under my skin by my neck and it hurts a lil what is it?

My be a cyst ,ganglion cyst , lymph node, fibroma or if red may be infection which needs antibiotics . If it grows or persists it needs evaluation. F/u/ w/ MD

It could be a lymph node or a lipoma a collection of small fatty tissue. Or other problem. You should see a doctor to see if any studies are warranted to elucidate the cause of this bump.