So do I have bronchitis if I cough up yellow think something?

Not necessarily... If you are coughing and also have a fever, nasal congestion, sore throat, body aches (or at least some of these!) then you probably have acute bronchitis. It is either viral or bacterial depending on the severity of symptoms (bacterial more severe). If you have a productive cough with none of the other symptoms that lasts at least 3 weeks, you may have chronic bronchitis. See your doctor for dx.