advice for possible flu?

my 7yr old started a sore throat Sunday. On Monday she was sent home approx 2 pm because of fever, I wasn't able to get her an appt that same day until Tue morning. that morning she tested negative for strep b? I think that's what is called, doctor said that the flu tests they had at her office were very inaccurate and even if she had it, she wasn't going to give her any medicine becuase she seemed healthy overall...today my daughter's cough is worsening and I don't know if I should schedule her another appointment??? she is not having a fever and we never knew is she really had the flu...I also have a 21 month old at home...what should I do? I just called the docs office and a nurse will contact me back but I've seen so many death cases that it freaks me out.