Heart Flutters

Tara
I'm 5 weeks and 1 day I've started to have heart flutters and shortness of breath really bad.  This is my second pregnancy and never had these symptoms before. I did notice in my previous pregnancy I wasn't able to take prenatals as they make me not feel good. This time around I bought the Rainbow Lite prenatals and started taking them for about a week now.  
This is when I started experiencing these symptoms.  I read online and found a few others that have experienced this and was wondering if anyone here has?? 
I'm going to go buy the chewable ones to try hopefully they help and don't give me these symptoms.