Was laying on left side when i felt a single very hard heartbeat. immediately sat up and felt another one. then they stopped. normal?

Normal: 'hard' heartbeats usually means that particular cycle was either pumping more or less than usual amount of blood. If its not exercise associated, and you are generally healthy, it usually means too much caffeine, or too little rest. Try less of one, more of the other. If it continues, consult your PCP.

Generally, yes: It would not be if it occurs frequently. Ask yourself, do I get chest pain with strenuous physically active? Do I get short of breath when I lay down, or with minimal exertion? Have I ever passed out? Do I have a family history of sudden death in the family, including at a young age. If so, you should consider going to a heart doctor.