Help bad cough for a week!?

I've had a bad cough for about a week now. Sometimes when I'm talking I choke because I cough. I don't have asthma or any allergies. It's a dry cough. I also didn't have a cold or the flu or a fever, it just started as a small cough, and got worse. I'm going to the doctor soon, but does anyone know what this might be?