Ultrasound or not...

Mae • First-time Mom. Baby boy born at home on 4/13/17. Christian. Loving wife. Career-woman.
I'm scheduled to have my first ultrasound today at 6w2d but it's only because the doc said I could not because I needed to. Now I'm having second thoughts. If no reason to expose baby to the ultrasound, why should I this early? I'd love to hear the heartbeat, but that's me being selfish.