HCG levels...

I got a call from my doctors office today and the lady told me my results from the blood test I had taken last Thursday. My HCG level was 1,786 at 6 weeks pregnant. I also had an ultrasound done that day as well. I got to see the baby & also heard the heartbeat :) I was looking online and it said normal HCG levels for 6 weeks pregnant are between 1,080-56,000. That's a pretty big gap.... Should I be worried? Is my level considered low??? I go back to the doctor Friday!!! Thanks for any of your comments :) I appreciate them!!!!