hi, my 19 yr old son has been suffering from a cold. he went on Monday to an urgent care and was tested for strep and mono, both negative, he was sent home with a zpack and has been taking it. he still has a low grade fever, sore throat, coughing up phlegm and generally tired, I have encouraged liquids and soft foods. he is out of state at school and is just doesn t know what to do. my instinct is its a cold and to let it run its course