What exactly is a biochemical pregnancy? The first meeting and union of the sperm and the egg occurs in the fallopian tube. While the fertilized egg, the seed, is developing, the endometrium, like the land, is actively preparing for the arrival of the embryo. When the development of the embryo and the preparation of the endometrium are in step, the embryonic blastocyst and the endometrium in a receptive state come into further intimate contact, and on the 5th-6th day of conception, the embryonic blastocyst burrows into the soil of the endometrial layer and begins to take root, and the embryonic trophoblast establishes a close connection with the endometrium, which is the implantation of the embryo. A biochemical pregnancy is one in which the embryo has already bedded down and the beta-HCG secreted by the embryonic trophoblast has entered the maternal bloodstream and can be detected by biochemical methods, but has not yet progressed to a stage where the gestational sac can be examined by ultrasound. It usually occurs between 22 and 32 days of gestation. If the pregnancy continues to the stage where the gestational sac can be detected in the uterine cavity by ultrasound, then it is called a clinical pregnancy. Thus, biochemical pregnancy refers specifically to the early stages of pregnancy. Embryos in the biochemical pregnancy stage can either continue to develop or wither and die. A biochemical pregnancy does not exclude the possibility of a potential ectopic pregnancy. In a biochemical pregnancy, the embryo stops developing for some reason and the beta-HCG level in the blood drops, when the ultrasound does not yet show the presence of a gestational sac, and we explain to the patient that this is a biochemical pregnancy. The mechanism for the occurrence of a biochemical pregnancy is still unknown and may be related to the developmental potential of the embryo itself, the tolerance of the endometrium, the hypercoagulable state of the maternal blood, and the immune dysfunction of the placental interface. Gently I go, as gently I come. Embryo loss that occurs during biochemical pregnancy is like a cloud that drifts through life. So, you don’t need to be surprised and you don’t need to dwell on it, just take care of your body and prepare for the next pregnancy!