How do you know if you having MC?

According to my last period I'm 6weeks pregnant Today around 7pm I started bleeding. So I went to the emergency room. They did ultrasound lab work and vaginal ultrasound and exam they said my hormone level is at 200 but the good news is my cervix is closed and bleeding and cramping were mild but they didn't see anything in the ultrasound maybe because it's too early or it's a miscarriage or possible tube baby any information would help I'm just scared and I will be following up with my obgyn tomorrow thank y'all