The brown color on the first day of menstruation is mainly because the endometrium has just started to shed, the shedding is slow, the amount is small, and the blood stays in the vagina for a long time, so the color is brown. On the second and third day, if the endometrium sheds quickly, the blood volume is high and the color is bright red, this is normal. Generally, on the first day of menstruation or when it is about to end, the endometrium sheds slowly and the color becomes dark, brown or curry, all of which are normal. Generally, it is normal to count from the first day of brown to the end of the brown color within a week. So the first day of your period or the last day of your period is a small amount of black coffee color. The middle is bright red color, the total volume of menstruation can be controlled in 30ml-50ml, this situation is normal. The first day of your period is brown, so don’t worry too much, it’s normal to be brown on the first day of your period.