After abortion, the black color of menstruation after one month means that the amount of menstruation is relatively small, and the small amount of vaginal bleeding will turn brown or black when it meets the acidic secretion in the vagina, so you can observe it for the time being. Because abortion is an artificial termination of pregnancy, the endocrine will be affected, the first time you have a period because the endocrine has not returned to normal, may be the ovulation is not normal caused by the decrease in menstrual flow, usually after 2-3 months after the period will return to normal. If the amount of menstruation is still very low or black after 2-3 months, it means that the amount of menstruation is too low, which may be due to the damage of the uterine lining caused by abortion or adhesions in the uterine cavity, and hysteroscopy is needed.