1,066. Finding a Stain

153:2 Even if a woman didn't feel the blood issuing from her uterus, but rather she found a blood stain on her skin, on her undergarments, on her bed linen, or anywhere else, if she cannot attribute it to any cause other than that it came from her uterus, then she is ritually unclean. If a woman finds a stain, if it's not exactly red and it's not exactly white, then she must consult with a Torah authority on the matter because there are many detailed laws regarding the size of the stain. There is also the matter of whether there is another cause to which she might attribute the stain, as well as when she found the stain - during her "pure" days or while counting her seven clean days.

153:3 If a woman feels her uterus opening, even if she checks herself immediately after and doesn't find anything, she is considered ritually unclean. Women should be taught this because many of them don't know this important law. However, if she checks herself and finds that what issued from her was only white, without any red mixed into it, then she is ritually clean.