Implantation bleeding is uterine in origin and does not result from a wound, and may render a woman niddah just like menstrual bleeding. A woman who becomes niddah as a result of implantation bleeding waits the five days and then counts seven clean days.
However, with both implantation and menstrual bleeding, there is a distinction between an actual flow of blood (which will render a woman niddah), and staining (which may not, depending on the circumstances in which it was found).
Stains found on toilet paper may be disregarded and do not render a woman niddah as long as at least a few seconds elapsed after urinating before wiping. In a case of doubt (you do not recall whether you waited before wiping) you may disregard the stain as well. Only if you are certain that you wiped immediately, and the stain was clearly reddish, would you be rendered niddah.
In addition, stains found on colored underwear or on disposable pantyliners may be disregarded and do not render a woman niddah. Please see our article on stains for more details.
Going forward, we recommend taking the precautions described above while you are tehorah in order to prevent becoming niddah unnecessarily from any irregular staining.
Please feel free to get back to us with any further questions.
B’Hatzlacha!
This response was updated on 8 February, 2024.