Everyday there is a black stain in my underwear, it's black as ink, it's not a discharge from my vagina it appears to be from the urethra and no smell?

Please see a doctor: Any stain needs to be evaluated. The tissues in and around your urethra and vagina can become delicate and fragile and can break down causing some bloody stain that can change color to black when it stays longer or dries up. you need to be seen for better evaluation.

Black stain: Follow up with doctor/urgent care this week. May still be from uterus ( if it is in) or from urethera or even from anus. Needs follow up.

See a doctor: Whether the black stain is coming from the urethra, vagina or rectum, it is abnormal and should be evaluated by a doctor. The color suggests the possibility of blood in the discharge, and this could signal a serious problem.