I'm a teacher and don't get many opportunities to go to the bathroom. When I went at 12:30, there was nothing. However, when I just went again now, I noticed a brown spot in my underwear. Now it looks brown but I am wearing hot pink underwear, so I'm not sure if it's red or brown or not. Anyway, when I wipe, there is nothing there on the paper. However, it's just a round spot, smaller than a dime, on my underwear. Should I call my doc? I have no idea if it's blood or from "the other end." WWYD?