The night of implantation will affect the HCG and progesterone in the blood, the longer the time of implantation, the higher the HCG and progesterone values will be, if the time of implantation is late, it will cause the values to be low. However, with the prolongation of pregnancy, the blood value will increase, it is best to take regular blood tests to review. If the blood value is very low, it will easily cause miscarriage, and it is best to use progesterone under the guidance of the doctor to treat it. If the blood HCG value does not increase with the prolongation of pregnancy or the HCG in the blood does not double every other day, it may be caused by poor embryonic development or ectopic pregnancy, etc. It is recommended to carry out ultrasound examination in time to see the development of the embryo and exclude ectopic pregnancy. If the ultrasound examination of the embryo development is normal, simple low blood HCG value needs reasonable use of medication. After the embryo transfer, you need to rest in bed, do not exercise strenuously, and do not have coitus, so as not to cause miscarriage and so on.