What I was having were premature atrial contractions (PACs). I know that womens' heart attacks can present differently than mens', and plus I'd had shoulder pains the day before, all of which was making me tremendously anxious. So I really didn't want to be one of those people who says "OH IT'LL GO AWAY ON ITS OWN" and then drop dead of a massive coronary a day later. :D

I did get them to show me my EKG, which was pretty interesting. You could actually see the PAC happening! Amazing. I love science.