i've developed a weird chest pain. sometimes my stermun cracks when i stretch my arms over my head. a chiroprator said this isn't unusual. but one day while using the tricep pushdown machine i developed pressure and then pain right in the middle of my chest. it doesn't seem to be going away. and now when i stretch my arms over my head all i feel is pressure like someone is pushing on my sternum. anyone ever experience anything like this? i'm gettin it checked out by another doc just to be sure.