Hi, my son is 12 years old. I took him to the doctor on Wednesday due to a high fever of 102.8 and swelling in the neck. They did a strep test, a test for mono and then a test for meningitis, a blood test and a test for the flu. Everything came back negative. He fever has since gone down, but he still has slight swelling in the neck, a persistent head ache and now he is vomiting. Do you have any thoughts on what might be wrong? Thank You