If the stain was found on a white garment (as opposed to white toilet paper or disposable pantyliners, which are subject to leniency) and it was at least the size of a gris (about the size of a US dime or Israeli shekel), you should bring the stain to a halachic authority for evaluation.

If you no longer have the stain and it was larger than a gris and clearly pinkish, you should assume it rendered you niddah. You need to complete the minimum wait before performing a hefsek taharah and counting the seven clean days.

If you no longer have the stain, and are unsure of the size and/or color of the stain, if it was found externally (i.e., not on a bedikah) there is room for leniency and you may disregard the stain.

See our article on Stains for more details.

Going forward, we advise wearing colored underwear at all times, and waiting at least a few seconds (ideally 15 seconds) after urinating before wiping, in order to avoid becoming niddah from stains. Particularly at this point in your life, staining can be erratic and you may not be prepared for it, so you should take these precautions at all times.

Please feel free to get back to us with any further questions.

B’Hatzlacha!

This response has been updated to reflect the rulings of our current Rabbinic Supervisor, Rav Kenneth Auman, regarding waiting before wiping.