What Causes Elevated Pulse Rate And Heart Fluttering Post Preterm Labor?

I went into pre term labor 3 days ago at 19 wks 5 days. Gave birth to a still born. I was released from hospital on Tuesday. I check my BP 3 times a day. I ve noticed that my pulse rate has been 105 114 and 124 while laying or sitting. Also I m having diifficulty breathing and I have heart flutters. Is that something I need to call my doctor about or go to ER for?