For those of you who are interested, or are having HCG monitoring, here are the suggested reference ranges:

Weeks Post LMP / Approximate HCG

3 - 4w: 9 - 130
4 - 5w: 75 - 2,600
5 - 6w: 850 - 20,800
6 - 7w: 4,000 - 100,200
7 - 12w: 11,500 - 289,000
12 - 16w: 18,300 - 137,000
16 - 29w: 1,400 - 53,000
29 - 41w: 940 - 60,000

These should be used as a guide only. HCG levels double approximately every 48 hours during early normal pregnancy and you should always discuss your results with your Doctor if you have any concerns.