What is the color brown on the first day of menstruation?

The color of the first day of menstruation is brown, mainly because the endometrium has just begun to fall off, the shedding is slow, the amount is small, and the blood remains in the vagina for a long time, so the color is brown. Wait until the second day and the third day if the endometrium falls off quickly, the blood volume is more, and the color is bright red, which is normal. Generally, the first day of menstruation or the end of the period, the endometrium falls off slowly, and the color will become dark, brown, and brown, which are normal. Generally from the first day brown start count, to the end of the last brown can be within a week, this is normal. Therefore, the first day of menstruation or the last day of a small amount of black coffee. The middle is bright red color, the total amount can be controlled in 30ml-50ml, this situation is normal.