5 week 6 day ultrasound, no heartbeat

Is anyone else experiencing this or have they in the past? I got a 6 week ultrasound and my doctor said it was measuring at 2mm (5 weeks and 6 days), there was a fetal pole, but no heartbeat. I am of course so worried and have another ultrasound next week. I've heard it could be too early and next week the heartbeat could be there. Can anyone give advice or their stories? I've seen so many things about how it could be a mc or it could just be too soon. Thank you in advance. ❤️