Refer please to the chart below from www.babymed.com. This totally calmed my nerves.
NORMAL HCG DOUBLING TIMES
| HCG Level | DOUBLING TIME EXPECTED |
| Under 1,200 mIU/ml | Between 30 and 72 Hours |
| 1200-6000 mIU/ml | Between 72 and 96 Hours |
| Over 6,000 mIU/ml | Over 96 Hours |
hCG levels rise during the first 6 to 10 weeks of pregnancy then decline slowly during the second and third trimesters.

Re: For those questioning doubling hcg levels