Sometimes we are so busy living life that we miss some of the lessons it is teaching us. "Oh that little pain is nothing.... I need to finish this thing I am working on, I can just take a aspirin and go on."
That may be true, but it may be that your body or life is trying to tell you something and you should probably listen. Where is the pain? How long has it lasted? Is it moving around?
The first thing one should do is to consult your physician about the pain, it may be something big or something that should be treated in some way.