My 11 year old daughter has been sick for almost two weeks. It started out with a sore throat and some stomach pain. I took her to the Dr a week ago and they tested her for strep and flu and both came back negative so they diagnosed her with an upper respitory infection. The dr said it was probably just a virus and she would get better, no medications were prescribed. Since then she has developed more congestion in her sinus and continues to complain about her head and stomach. She has had hardly any appetite at all since this started but is drinking fluids. She is also very tired and just wants to sleep and has no interest in playing or anything. She has not been running a fever or throwing up nor dies she have a rash of any kind . Just says her stomach and head hurts although when I push on her abdomen she does not have any sensitive spots. her lack if eating and tiredness is causing me concern because she is already on the thin side.