Early bleeding in pregnancy may involve female hormones, fetal chromosomes, and some embryos that are not developing well themselves can cause early bleeding. Some female hormones drop, such as progesterone and HCG drop can cause early bleeding. It can also be seen in the following causes: 1. viral infection: infection by other viruses such as macrophage virus that invade into the milk ducts may cause bleeding in early pregnancy; 2. immune system abnormalities: some immune system diseases can cause early bleeding, such as positive antiphospholipid antibodies and positive anti-thyroid antibodies; 3. endocrine abnormalities: such as hyperthyroidism, diabetes, poor blood sugar control, etc.; 4. vigorous activities: more strenuous sexual life or lifting heavier objects can also lead to bleeding in early pregnancy; 5, genital inflammation: such as vaginitis, cervical polyps, etc.; 6, other: uterine bleeding related to pregnancy should be excluded, the common ones include miscarriage, ectopic pregnancy, gravida need ultrasound examination to confirm the diagnosis. Early bleeding definitely affects pregnancy, timely hospital consultation, to do further treatment under the guidance of a doctor.