A single measurement of hCG cannot be used to determine the gestational age or even to estimate a due date. The laboratory that processes most of the specimens from my office recently stopped giving a reference range as this was completely worthless. The following are the reference ranges previously quoted: 1 week since conception: 5-50 mIU/ML hCG 2 weeks since conception: 20-500 mIU/ML hCG 3 weeks since conception: 500-5,000 mIU/ML hCG 4 weeks since conception: 3,000-19,000 mIU/ML hCG 8 weeks since conception: 14,000-169,000 mIU/ML hCG 12 weeks since conception: 16,000-160,000 mIU/ML hCG So, as you can see, there is a considerable amount of overlap. . The Pregnancy Hormone - hCG. Beta hCG Test (Pregnancy Blood Test) Human chorionic gonadotrophin (hCG) is a hormone produced during pregnancy that is made by the developing embryo after conception and later by the syncytiotrophoblast (part of the placenta). In most cases hCG levels will double every 31-72 hours in early pregnancy.. Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Ingram on hcg level 5000 at 5 weeks: Say? And what are the Progesterone levels? , high levels are reassuing, low levels are not, but it does not appear to be that your bhcg is going up properly now because it should double every 3 days and go up by 66% every 2 days and the last one did not, once u are 6 - 6 1/2 .