If the time of menstruation does not come, the appearance of black and dark stuff is considered to be blood, except that the amount of blood is small and the blood stays in the vagina for a long time, and this black and bloody discharge appears. First do the early pregnancy test to see if you are pregnant, pregnancy can also appear this small amount of bleeding. It is common to have a small amount of black menstrual discharge in cases of preterm miscarriage or in cases of ectopic pregnancy. If pregnancy is ruled out, it is important to see if there is a problem with the cervix. If the blackness is due to ovulation or luteal phase, do an endocrine test to see if it is due to an endocrine disorder. If you have a menstrual period, generally consider that there is a deficiency of qi and blood, or a cold in the uterus will appear this low volume of black menstruation, to regulate the symptoms. Be sure to go to the hospital to do the appropriate examination to find the cause of the low blood volume, and then the right treatment.