Hi, I'm a 23 year old male, approx. 6'2 180 lbs. I have been lifting weights for over a year now and have never had any problems. Three days ago I was on the bench press doing my normal warm up routine and I heard a loud pop in the left side of my chest. Following this the left side of my chest and back began to hurt, the pain worsening when I breathe. I had x rays taken, and nothing was found. I was wondering if this just sounds like a strained muscle, or if there could possibly be more going on.