Hello, I am 20 years old, turning 21 in a week. I have been extremely active the last 3 months; going to the gym and running every other day with one day off per week. About 3 weeks ago after about a week of starting my pre workout, I noticed a "thump,thump" in my cheset/throat while lifting rather heavy weights. It scared me, I suddenly feared dropping dead because of these palpitations. These are nothing new, I have felt them before, i just feel that now that I've googled and found many possible causes of what they might be i'm freaking myself out. I took a week off from the gym, and started up again yesterday. While working out I felt maybe 2-3 individual flutters throughout my session. Today however, all day I have been thinking about the palps and this last hour or so, I feel like I have been getting them quite often. Does this sound like stress or a serious heart problem?