Confused.

Started bleeding and went to the emergency room last week. They said I wasnt far along enough to see anything on the ultrasound.:( they told me it was a threatened miscarriage. I followed up with my OB a few days later. He was booked. I gave them 2 blood test before my appoitment. I had my appoitment and he said my cervix was still closed, but we need to figure out why I was bleeding. He said I could have had twins and one passed away. I'm just very confused. I have another appoitment on Tuesday.