Hi,
I quit smoking and felt chest pressure/tightness for quite some time afterwards, it's normal, your lungs are healing.
Thought it was cardiac related, had cardiac tests done, results returned normal, had pft done, results returned normal. It will pass, relax congratulations, kickin the habit.
You do what makes you feel right. Ask your dr. to refer you to a cardiologist. If you did quit smoking just recently then you will be coughing up "gunk" for awhile. Or if you do feel better going to a lung specialist, then ask her. Remember, they work for you.
Good Luck