Girlfriend has sharp chest/lung pain and cramps in the bottom right of her stomach as well as a slight headache and sore muscles. any clue?

Varied symptoms: These varied symptoms may not be interrelated or caused by one disease process. In this case a physician would take a thorough history and system review, perform a complete physical examination and order appropriate tests in order to make a diagnosis. A flu like viral infection may be what's going on but cannot be diagnosed without a thorough evaluation and examination. Take fluids,Tylenol for now