Aunt, why is it dark brown?

The reasons for aunt showing dark brown are generally considered, mainly because of the following reasons, caused by the first, if there is sexual life, first consideration, because of pregnancy, related diseases, mainly seen in the following, the first, possibly normal, early pregnancy reaction, because at the time of embryo implantation, endometrial instability will occur, thus causing a small amount of bleeding, the second, It may be caused by threatened abortion. The third type is the most serious. It may be caused by ectopic pregnancy. Therefore, it is necessary to go to the hospital as soon as possible to determine human chorionic gonadotropin. The second type. If there is no sexual life, or pregnancy can be ruled out, it may be caused by ovarian dysfunction or decline. Specific needs to go to the hospital to do female hormone six items, amh, and gynecological color Doppler ultrasound to make a diagnosis. Generally, after examination, it can be clear. Aunt, why is it dark brown?