What can cause sudden sharp pain in centre of chest? that goes away just as quick. i then felt like i couldn't breathe. heart was racing and pounding. dr said i felt pain then maybe had panic attack. im worried it could be a clot. they not testing?

A sharp pain in your chest at your age is most likely from the stomach entrance, located just in back of your heart, from acid backwash through that entrance. The best "test" is having the doc review your history and do an exam. You would be dead if it was a pulmonary embolism. Testing for the heartburn is diet alteration/avoid caffeine/spicy foods, antacid tablets.