Fetal Arrhythmia at 23 weeks doppler

Liz
Hi! I am 23 weeks and 4 days now and at my appointment, Monday, the babies heartbeat sounded really irregular and the doctor said it was an arrhythmia, but it can happen due to heart maturation and she isn't concerned about it. I called back because I don't know enough to not be concerned was told the doctor didn't even note an arrhythmia in my chart! 
Has anyone dealt with this? What did you do? What was the outcome?