The halacha indicates the need for white clothing during the shivah neki'im but does not specify which clothes. In an era when women did not wear form-fitting undergarments, it was important that all the clothes on the lower half of the body were white. Now that women generally wear underpants, and any stain from the vaginal area will be visible on her underwear, there is no obligation to wear additional white. If a women wishes to do so, she of course may.

The requirement to wear white applies only during the shivah neki'im because at this time we are trying to assure that bleeding has not restarted. On the other hand, when a woman is not in niddah, she is best advised to wear colored underwear, on which stains can be disregarded.

Your kallah teacher is correct that a real flow of blood (as opposed to staining), would make you niddah. In general, staining that could be contained with a single light pantiliner over the course of a day would not be considered a flow. But if you aren't wearing a pantiliner, such staining could still be heavy enough to leak through your underwear onto your slip. A stain found on a white slip would then be evaluated based on the laws of stains. (Learn more about the laws of stains, and the distinction between staining and a flow, here.)

Whether the stains you found make you niddah would be based on the criteria for stains. A stain can only make you niddah if:

• At least one individual stain is larger than a gris (about the size of a US dime or Israeli shekel coin).



• The stain is a niddah color.



• The stain is in a location where it could plausibly be from uterine bleeding.

Furthermore, a stain would not make you niddah if there is another reasonable explanation as to where it might have come from. In this case, it sounds like you didn't really check the slip before putting it on, and the stains look like they might have been old. That would also be a reason for leniency.

If you are still in doubt, you should consider yourself to be possibly in niddah, and get back to us (or our hotline for a quicker response) or to a local halachic authority, with all the details.

In the future, you can avoid this type of situation by wearing disposable pantiliners when you are not in niddah and are wearing a white slip or skirt. We follow the position that stains on disposable pantiliners do not make a woman niddah.

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