biochemical precursor to pregnancy

Biochemical pregnancy is a particularly early pregnancy, occurring within 5 weeks of pregnancy or even before the next menstrual cycle. When sperm and egg cells combine to form a fertilized egg, enter the uterus, ready for implantation, the embryo begins to secrete β-HCG, at this time urine and blood tests can detect pregnancy, but ultrasound can not see the gestational sac. After that, due to various reasons, the embryo did not continue to grow healthily and stopped developing. The hCG in the blood decreased accordingly, and the gestational sac could not be seen by B-ultrasound examination. Many times, the bleeding of biochemical pregnancy abortion coincided with the next menstruation. If you did not go to the hospital for special examination, it would not even be discovered.