My 5month old baby have running nose and a terrible chest cold.. took her to the doc and they did nothing! it's 2 weeks now and no change?

Chest cold: After two weeks of a chest cold one has to consider the possibility of pneumonia or bronchitis. Return to your doctor or the er for a chest x ray and possible further treatment.

Viral bronchiolitis?: Bronchiolitis is a common lower respiratory tract infection that most commonly affects babies &young children under a year old. Most cases are mild &improve without specific treatment within about 2 weeks. If your baby's symptoms are more severe, recheck and perhaps consider nebulizer with albuterol treatments for cough/wheeze. Saline drops are the mainstay with upright positioning/steamy baths.