I have a dull pain in my chest, and I'm worried that something is wrong with my lungs. What can I do?

Go see your doctor. What can you do about a concern about your lungs? Perhaps you should go see your doctor. I am amazed at how many specific health questions are posted without any history or symptoms being provided. And I am equally amazed that someone would think they could be diagnosed by a web site on the internet. If you are concerned about your health, your doctor would be the person to see. In person.
See your MD. See your primary care doctor and/or a pulmonologist to rule out lung disease with an exam and a chest x-ray.