A small amount of blood in the early stage of pregnancy is considered to be caused by fertilized egg implantation, ectopic pregnancy, early miscarriage, and diseases of the reproductive organs. 1. Fertilized egg implantation: the endometrium is locally damaged when the fertilized egg is implanted, and the endometrium will be repaired automatically. A few women will experience a small amount of bleeding when the fertilized egg is implanted, and there are usually no other abnormal symptoms, so there is no need to deal with it. 2. Ectopic pregnancy: the fertilized egg needs to enter the uterus through the fallopian tube, if it doesn’t normally settle in the uterus, but settles in a location other than the uterus, such as the fallopian tube, the embryo can’t develop normally, and at the same time, the fallopian tube is eroded, which will lead to bleeding. 3. Early miscarriage: Embryo has the ability of self-elimination, if the fertilized egg is of poor quality or chromosomal abnormality, the embryo will stop developing or be underdeveloped, and spontaneous miscarriage will occur. 4. Diseases of reproductive organs: If there are diseases such as uterine fibroids, endometrial polyps, cervical polyps or even cervical cancer, abnormal vaginal bleeding also occurs. A small amount of blood in the early stages of pregnancy may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.