My Daughter Is 8 And Has Had A Cough For

My daughter is 8 and has had a cough for 3 weeks. Told it was virul and to let it run its course and the cough my linger. She just started in the last 10 minutes complaining of pain when she tries to sit or lie down in her lower throat (trachea area??) throat is not red and her breathing sounds fine. Wondering if she is having acid reflux or maybe gas pain...just want to rule out any bronchial problems for tonight