Experiencing pain in left outside edge of rib cage; no cough, cardiac ruled out, hurts to lie on at night. Radiates down arm; fasciculations. Ideas??

Musculoskeletal? Greetings to my old hometown! I'm a runnin' Ute. Symptoms sound musculoskeletal, particularly how they run down arm and are aggravated by lying on affected side at night. If you are a smoker I'd start with a chest X-Ray to help rule out intrathoracic pathology. If not, then I'd give nonsteroidals a shot, say Ibuprofen 400mg three times a day for one week if no allergies to the same. Then, see MD.