Bleeding on implantation is a normal phenomenon. Pregnant women may experience a small amount of vaginal bleeding or brownish discharge during the process of implantation of the fertilized egg. A woman’s discharged egg and a man’s ejaculated sperm meet in the juxtaposition of the fallopian tube through some kind of sexual intercourse and become a fertilized egg. With the help of the cilia of the fallopian tube, the fertilized egg gradually moves inward to the uterine cavity, where it finds a nutritious place to settle and develop further, i.e., implantation, which is known as pregnancy (intrauterine insemination). The fertilized egg secretes a substance that destroys the lining of the uterus during the process of implantation, creating a depression for the fertilized egg to stabilize, after which the destroyed lining of the uterus will repair itself. Some pregnant women may experience a small amount of vaginal bleeding or brownish discharge, which is called fertilized egg implantation bleeding, mostly occurring 2-3 weeks after the formation of the fertilized egg. In addition to a small amount of vaginal bleeding, mild abdominal pain may also occur, which is normal. Since a small amount of vaginal bleeding in early pregnancy is also common in cases of preeclampsia, ectopic pregnancy, etc., the pregnant woman herself can not determine what causes the bleeding, therefore, in order to rule out the occurrence of abnormalities, pregnant women need to consult a doctor in a timely manner after the discovery of vaginal bleeding, especially when accompanied by obvious abdominal pain, in order to avoid the rupture of ectopic pregnancy, which can lead to fainting, shock, and so on, need to be near the doctor immediately. To sum up, bleeding in pregnancy is caused by the destruction of the uterine lining when the fertilized egg is deposited, which is a normal phenomenon, but no matter what the cause of bleeding in early pregnancy, it is recommended that pregnant women consult a doctor in time.