not sure about my hcg levels

Heather
I had a miscarriage back in February of this year. I am currently pregnant and recently had my hcg levels checked a week ago and then again yesterday. My first level was   153 and my level from yesterday (a week later) is 1787. My doctor says it's not as high as she would like and wants me to come in for an ultrasound tomorrow. Should I be worried?