Hoping for the best expecting the worst

Ultrasound @ 5 weeks, 6 days was great, heartbeat, yolk sac, gestational sac & fetal pole all found. About 6 days later I went to the ER for some pelvic pain not too severe my OB said if any pain after hours go to the ER. So the ultrasound at the ER showed fetal pole, yolk sac, gestational sac but no heartbeat. Has anyone experienced this before? What was the outcome? I know all pregnancies are different. Thanks.

I have an appointment tomorrow for another ultrasound.