HCG, commonly known as Human Chorionic Gonadotropin, is mostly treated as a hormone that is produced when the woman becomes pregnant. During pregnancy, all of the process actually takes place under thick blood vessels that is commonly known as placenta. And this placenta is formed by HCG through cells. The function of HCG is first to welcome the serum and then helps in making nourish the egg that has been formed at the very early stage and then that eggs get fertilized with the help of HCG and then that egg link with the special wall name as wall of uterine that helps in making fetus all and all that. Pregnancy level can be tested in first eleven days through blood test and in fifteen days through urine test. As strong as HCG level would be, the most will be the chance of pregnancy level. It continues to grow for about ten weeks and after that HCG level starts going down with slow rate.