About 2 months ago i had a spasm in the left front of my chest for about 10 seconds. Never thought anything about it but over the weeks i am having upper left back pain and at the end of my breath. I also feel pains in my left armpit and behind my boob. I am starting to worry it's my heart or lung. The only thing that makes me think it's not is if i get someone to rub on the back of my ribs/muscles feel bruised and sore and an osteopath said all my left felt stiff.