Ever since I was little (and can remember) I've always gotten a weird pinching/stabbing (would hurt to the point where I couldn't breathe up and down) feeling in my upper chest area for a few seconds. It's not in my actual chest (like in between both of my breasts). It's more like in the upper part of my breast tissue. If it helps, I've had shortness of breath easily since 2 years ago. Sorry if none of this makes sense. I've just always been worried/concerned about this since I was little. It doesn't ever happen after heavy lifting. One time I even got it randomly while sitting in the car waiting for my mom.