2002 Honda Civic Rattling, Clatter noise

I have a Honda Civic 2002 Automatic an it is making a rattling noise close to the passenger side. I thought it might have been the transmission fluid but I just topped it off and it still makes the noise. It sounds like a flat tire or like rubber or metal is repeatedly hitting against the tire or something other. I need advice or some kind of an idea of what it just might be before I take it to the auto shop. I don't want to pay an arm and a leg for a part I can put in myself or repair.