Miscarriage questions

Tiffany
I found out I was pregnant on 11/24. I started cramping 11/25. I went to the ER due to cramping and bleeding on 11/27. No ultrasound was done, only a blood level and the doc told me my HCG level was 300, and was told i had a m/c. However, 300 would have been exactly around what my levels should be for ring 1-2 weeks. If I tested today on a clear blue digital and it said "pregnant 1-2" would it be a false postive? I'm so confused and emotially drained from this!