Intermittent Heart Palpitations While Resting Along With Heart Burns, Headaches. Serious?

I have been having heart palpitations these past few days and they are beginning to concern me. I have experienced these in the past, but not with the same severity. It feels as though the wind is being knocked out of me. It doesn t happen when I am exercising or anything. It usually occurs when I am just sitting there. It has been getting worse. Today it has been happening at least 2 times an hour. Now I am experiencing some heart burn and occasional head aches. I tried to call my doctor to schedule an appointment,but the office was already closed. I m just not sure if I should wait to hear back or go to urgent care or to the hospital. In the past I was told it might just be a random thing that I had to live with. So I don t want to make an unnecessary trip to the hospital. But I also don t want to blow off something that could be serious.