What is that nasty smelling blood at the end of your period?

The "nasty smelling blood" you experience at the end of your period is old blood and tissue shedding from the lining of your uterus. During menstruation, the lining of your uterus breaks down and sheds, and this material, along with some old blood, is expelled from your body through the vagina.

The smell of the discharged blood during the end of your period is more noticeable. This difference in odour has to do with changes in pH or acidity and bacterial flora within the vagina during menstruation. At the menstrual cycle’s end.