is it possible that you are further in to your pregnancy than 8 weeks? I ask this because HCG
levels during the first trimester will peak sometime around 9 to 12 weeks of pregnancy, at somewhere around 25,700 to 288,000 mIU/ml. By the final weeks of the first trimester week 13 and 14, hCG levels are finally on the decline, and will be at around 13,300 - 254,000 mIU/ml.
From there, hCG levels tend to continue the downward change into the second trimester.