Threatened miscarriage...

Went into the ER on 7/15 because I started bleeding, ran blood work and also had a vaginal ultrasound. The ultra sound was inconclusive because I am not far along. They told me to come back in 48 hours to test my hCG levels again to see if they are going up or down. Went back today 7/17 and my hCG levels have gone from 483.9 to 708.9! I’m so confused and concerned! Am I having a miscarriage or not 😭 this is my first pregnancy. I did pass a large blood clot after my ultrasound and the bleeding has gone down a lot I am now only having light pink and brown blood when I wipe. Has anyone else experienced this?? Is this normal?? Should I be concerned?? I don’t want to lose my baby 😭