What exactly is bronchitis and is it contagious and is it dangerous i've been coughing real bad and people keep asking me if i have it and i don't kno?

Bronchitis: Means "inflammation of bronchial tubes" usually associated with wheezing as well as cough.

Lung infection: Bronchitis is an infection of the upper airways. The cause is either virus or a bacteria, more frequently a virus. Other cause of these symptoms could be a pneumonia which is an infection of the lower airways. Bronchitis should be considered contagious, so cover cough, wash hands, etc. Consider medical evalution and a chest xray if concern.

Infection: It is a lung infection. If you are not on any antibiotics and you have not been to your doctor the outstanding question then becomes why not?