I have a pain by my armpit on the left side. I have recently just started dieting and stopped smoking. I did not drink any pop today for the first time in a long time. It's not am extreme pain but more of a sharp pinch. I'm just very worried on what it could be. I'm only 18. I have no previous health issues with my lungs or heart or any other organ. I do get chronic pain in my back and neck every once in a while. Maybe when I cracked my neck I hit a nerve that is right next to my armpit. I don't know. Any help would be greatly appreciated! I've only just noticed this tonight so idk if its regular or not.