Baby Heart Arrhythmia at 37 Weeks

Definitely bummed about this appointment. I've have the perfect pregnancy and little boy has been so healthy and been measuring two weeks bigger since about 30 weeks! Then today at my appointment they heard an arrhythmia with the doppler. So now I have an appointment with a pediatric cardiologist to perform a fetal EKG next Wednesday. My Nurse Practitioner doesn't seemed concerned. She thinks he's just squeezing his umbilical cord and that this appointment is just a precaution but I'm still totally worried. I hate this feeling! Has anyone else heard an arrhythmia on their babies heartbeat? What was the outcome?