It is better to check the progesterone value, if the progesterone value is low, consider the possibility of pre-eclampsia, you should supplement progesterone in time. If the progesterone is normal and the ultrasound does not reveal any problem, it is considered to be bleeding caused by the process of fertilization of the egg, which is related to the hormone secretion in the body. In the early stages of pregnancy, estrogen and progesterone increase, there is a slight bleeding, do not be too nervous, relax, do not overwork and pay attention to observation.