The status of the pink stain on your underwear depends on its shade and size.
You can check yourself if the leniency based on size would apply. If the stain was clearly smaller in area than a gris (the size of an Israeli shekel or American dime), it would not have made you niddah. If there was more than one stain on the undergarment, the area of each stain would be evaluated independently.
If the stain was larger than a gris, determining whether it is a niddah color would require evaluation by a halachic authority. If you prefer not to ask your local rabbi, you may want to try Tahor App, which uses sophisticated color calibration technology to allow for evaluation via smartphone.
The status of stains on toilet paper depends on many factors, which we detail in our article “Toilet Paper“. Please read it and get back to us with further questions.
The stains on the pad would not affect your status, since pads are considered a surface on which stains do not make a woman niddah.
If you did become niddah from the staining, the day of the staining would be considered day one of your five-day minimum. On day five (or later) you would perform a hefsek taharah prior to halachic sunset, your clean days would begin that evening, and you would immerse a week later. (E.g., staining on Monday, hefsek taharah as early as Friday, immersion as early as the following Friday night.)
Since irregular cycles are very common among women in their early fifties, we suggest that you take precautions to avoid becoming niddah from stains. For example, stains on colored underwear do not make a woman niddah, so we suggest wearing coloreds when you are not in your clean days. (See our article on stains for more details.) Also, wait a few seconds (ideally 15 seconds) after urinating before you wipe; see our page on toilet paper for more details.
For the future, we do not recommend doing a bedikah just to see what will happen. Even a tiny amount of blood found internally can make you niddah in a situation where external staining would not have. Conversely, if external staining does make you niddah, a clean bedikah will not help.
This is a normal process, but if irregularities persist or if you have difficulty becoming tehorah, you may wish to consult your physician about the situation.
This response was updated on 13 February, 2024.