Thank you for reaching out to us.

If we understand you correctly, you have a general sense that a period might be coming, but have had only staining on colored underwear. Staining on a colored surface does not make a woman niddah, even if it persists for days. Therefore, based on your description, we would not consider you niddah.

If you have had niddah staining on toilet paper or on your inner thigh, then your status would depend on some additional factors. Learn more on our pages on stains and toilet paper.

Also, we usually recommend abstaining from relations for a day or some from staining. This is precaution against a flow beginning during relations, and not a halachic requirement. Learn more at the first link above.

Medically, you might want to take a pregnancy test and to book a non-urgent gynecological appointment, to be on the safe side.

Please let us know if we can be of further assistance.