Rheumatoid arthritis and chest pain ?

 My doctor at John's Hopkins childrens center diagnosed me with rheumatoid arthritis a few months ago. My parents and I are not convinced that RA is the proper diagnosis. The doctor couldn't answer any of my questions. I asked him several questions about the new symptoms that I had been experencing sine I saw him at my first visit. He couldn't tell me anything. He didn't run any further tests. Even when his diagnosis was based just upon a physical exam. One symptom that I am very concerned about is the chest pain that I am having. If my doctor has diagnosed me correctly with the RA, could the RA be causing my chest pain, and could this be a serious problem? Any answers...