Why does my Upper Sternum hurt?

Question

It only hurts when i flex my chest or move a certain way.

It hurts when i lay flat and flex it or do a sit up.

It hurts especially when i first wake up.

It Does not hurt when i just sit,stand still or walk around normal.

Does this mean i am having a sign of a heart attack?

Answer 1

A heart attack does not protract for multiple days. :-)

Obviously your pain is being caused by muscle sprain in your chest. If you wish to identify the culprit of this irritation, my advisory is that you either consult with a physical trainer, or schedule an appointment with a chiropractor. Both types, here, would be adequately familiarized with the mechanics of the human body, such as to ascertain the root cause of the problem, as well as prescribe the appropriate exercises and posture corrections that will ameliorate the issue.