I Went To Er Last Night And Was Told That

I went to er last night and was told that my urine sample came back positive and I'm pregnant. I told them I have been spotting very light since my last period on/off. They performed a vaginal exam and the blood test. But on the ultrasound he said he didn't see anything and released me with a possible miscarriage and follow up appointment in 4 days. Did I have a miscarriage?