I wouldn't worry too much about it. This started happening to me around a year ago. I'm 21 and have been an athlete all my life. At first it really scared me because I would have episodes of these skipped beats and flutters for hours. I was hospilized and also told I was completely healthy and put on a beta blocker. I cut out all forms of caffiene and alcohol from my diet. The episodes still remained, but after a while- I got so used to them and began to relax and noticed they went away quicker. A big part has to with the stress thats signaling your parasympathetic system to make your heart o faster. I now take deep relaxed breaths and it happens maybe once in a while with one or two skipped beats. I would also reccomend light exercise. It might trigger the flutter at first but breathe deep. Ive conditioned my body to control breathing and the exercise has even helped the flutter go away for months when I am working out consistently and lightly. I dont even need my beta blocker anymore. Don't let it scare you..it is such a common thing alot of healthy, young people live with.