In bed I can hear my heartbeat through my ear. Sometimes it is "thump-thump--thump-thump" and other times just "thump--thump." What are extra thumps?

Extra beats. it is not uncommon for a young person to have extra beats. These are beats that come from upper or lower chamber of the heart and do not go through the normal stop signals of the heart. They can be increased in number with caffeine, stress, lack of sleep. They are usually not harmful but should be documented by your MD. Usually clear when exercising.