Anxiety or Heart Problem?

I am a 27 year old female who is not overweight with normal BP and Cholesterol levels. This past week I have been having a rapid heartbeat off and on. After less than a minute it goes away but I have to lay down and take deep breaths (that only happened three times). I got my heart checked out by a cardiologist 2 years ago because my primary doctor thought I had inflammation around my heart (she thought this because my CRP level was around 5). I got a full work up done on my heart and they said everything was fine just to watch my diet and exercise. I am in professional school and have major tests tomorrow and Monday but I usually don't get like this. I am a hypochondriac though and ever since I had those rapid heartbeats I can stop thinking about it and I think I'm scarring myself. I try not to think about it but when I do which is all the time I get like this scared feeling in my chest like if I were going to give a speech or something and sometimes I feel it in my head. Could I be making myself do this or do I have a valve or heart problem? I had that full work up done at a heart hospital so is it possible they missed something? Also, could you please explain what the CRP is? I know it's a inflammation/warning marker, but does that mean I have plaque in my arteries? At the heart hospital they gave me some kind of calcium test or something that had to do with my heart and it was normal. My father died of a massive heart attack at 54 so I'm worried about this stuff. Thank you.

[hava]

Do this pranayam now and daily, and it will relax you and control the heartbeat.Try and do it before breakfast and then any other time.The effect is gradual and you will be glad, you can do something yourself.
Build up your timing gradually.If you feel tired or dizzy, stop and resume after one minute.
Anulom Vilom pranayam –
Close your right nostril with thumb and deep breath-in through left nostril  
then – close left nostril with two fingers and breath-out through right nostril  
then -keeping the left nostril closed  deep breath-in through right nostril
then - close your right nostril with thumb and breath-out through left nostril.
This is one cycle of anulom vilom.
Repeat this cycle for 15 to 30  minutes twice a day.
Children under 15 years – do 5 to 10 minutes twice a day.
You can do this before breakfast/lunch/dinner or before bedtime or in bed.Remember to take deep long breaths into the lungs.You can do this while sitting on floor or chair or lying in bed.