One month agao I had an enlarged painful lump on my neck next to my carotid. Dr. treated with antibiotics told me to have my dentist do xrays two weeks later during my routine visit he couldn't see any infection CBC was goo so he thought maybe dental. The lump went away with antibiotics, nothing found at dentist, he even did the full 360 xray just to make sure. So I didn't worry much after that. For the past two days I am having same syptoms, same side only this time lump is on base of skull. Sore, hurts when I bend head down. Should I be concerned?