I have the lung pains again!

Last year and at the end of 2006 I had throbbing pains in my chest. The pain was located in my back (but actually inside, like it was coming from my lungs) in the middle below my shoulder blades but slightly to the right (maybe the trachea?).
Anyway, I went to the hospital and they prescribed me some antibiotics as they thought it was a chest infection. They said if I get it again they'll need to "investigate".
However, the pain has come back at different times and only recently I've had the pain come back again. It seems to worsen when I exhale for a long time or when I yawn.
I'm also feeling very hot one minute and cold the next.
What do you reckon this pain is related to?

I have pains like that but I have asthma and thats what my pains are caused from other than that I dont know what they may be caused from