Good afternoon. My fiancé and I went to the urgent care yesterday with all of the classic flu symptoms...mild fever, chills, headache, dizziness, cough, chest pain, leg pain, and an outbreak of all over his body hives 2 days before that appointment. After the hives appeared, and then went away with some Benadryl, it was all down hill after that. However, they gave him a flu test, which I didn t know that even existed, and he tested negative. Is it possible that could be a false negative?