Last week I felt like I was having a heart attack. Bad pain in my left chest area. Had an ekg done, was told I could left so assuming nothing showed up. Also had a chest X-ray done. This pain dulled. But on Friday past out of the blue I get extreme pain in the centre of my back, I could not take a deep breath or even sniff without it hurting. I am very active and know my body and when I have muscle pain this is not that. I did notice that the pain in my left chest was between my ribs but not the rib itself. Any ideas?