I'm 16 and I have one about every 10 seconds. Of course you should get checked out like I did, I was put in the hospital last night but it turns out everything is fine and the doctor isn't even going to do anything about it. For young people it usually isn't reason concern and if you have a low heart rate it is even less of a reason for concern.
I came accross your post hoping for answers too. I am 24, great health, but i am getting these "quivers" or "flutters" in my chest. It will happen a couple times a week to two times a day. it is very scary. I feel like my heart it going to stop or something. I just saw a heart doc and did the ekg, ecg, and 24hr monitor. they are going to get back to me in about 2 weeks on the results. But just by telling him my symptoms, the doc has no idea what it is. Also, i do have panic attacks and get anxtious frequently. im thinking this has a lot to do with my problem.