I Went To The Doctor And They Did An Ultrasound

I went to the doctor and they did an ultrasound and they couldn't tell me how far along I am but they see a gestational sack then told me I might be having a miscarriage they don't know yet and then so I went to the hospital in the ER and they told me that I was 6 weeks 1 day and no heartbeat but maybe I'm not far along yet but they said it could be an early pregnancy or threatened miscarriage. I've had no bleeding at all.