Pleurisy?

I have been experiencing sharp back and chest pains for about a week now, I am a 25 year old female and smoke around 20 cigarettes a day.

The pain started after a particularly stressful day, I was getting sharp chest pains immediately followed by back pain. In the days that followed the pain continued intermittently, but I'm now I'm feeling constant pain all over my back. The pain is constant, doesn't worsen when I breathe and I don't have a cold or cough.

Yesterday I went to see my GP and he told me it was related to my smoking. Obviously he recommended I quit so I have cut down considerably with a view to quit altogether (this experience has spurred me into action).

Anyway, this morning the pain in my back was pretty severe so I made another appointment with a different GP to try and get some relief. She has diagnosed Viral Pleurisy and is sending me for a chest X-Ray.

Now I'm really confused, which one is it? Everything I've read about Pleurisy indicates that pain worsens when you breathe, and I'd assume the same would apply if it was smoking related.

Has anyone else had the same experience? Or any ideas what this might be? Should I be worried about the chest X-Ray?