Am I Having Heart Palpitations?

Hi, im 15 years old and i experience what i think are heart palpitations just randomly, my heart will be beating and then all of a sudden a really large beat will kind of disrupt everything. Im scared b/c they are happening more frequently no other symptoms really. I dont know what to do and dont want to worry my parents over this. i dont get alot of sleep and i havent been active the past few days. can anyone tell me how to stop these weird beats. My heart isnt racing either its just a regular pulse rate. they are just really annoying. should i drink more water? I just need some answers. They went away for a year then came back for a week, and went away for about 3 weeks now their back. help?