I noticed last night that I have this small sized ball kind of thing just behind my ear where the ear ends. I'm sure it's not a pimple . It's hard , under the skin ,small in size , does not move and is painful to touch . What can it be? Should I consult a doctor ? .. I don't think it's a swollen lymph node as its pretty small like half cm in diameterand since I don't have any infection and have perfectly fine health ...