My 11 yr old son has had a small lump/knot appear on the back of his head near neck , he says it is sore to touch. Now today he says his nipple is tender to touch/ press on. He also has slight sore throat and tenderness at the base of his ear. Our neighbor is an ER doctor , she gave him a quick look and said it was probably Mono, and he probably didn't need to be rushed to the doctor ? What is your opinion? I plan to take him in the morning anyway...