This sounds scarey for you! I know I get what are "chest" pains, and it takes me a moment to realize that it's my muscles spasming, in the chest area... and have to work on them with my hands,fingers to keep from knotting up... (can't use TENS around heart, I think?) Especially bad are they when my shoulders are strained..and the muscles that wrap over into the chest also spasm. As for those at the sternum, I can't even guess! Take care of yourself. Don't assume it's the same old thing, being nothing??? I, too, vote for a doctor's opinion.