When an onat perishah falls out at night, most authorities prohibit relations even on mikveh night. There is debate about whether immersion itself is permitted for the purpose of other physical contact. Our site’s rabbinic supervisor, Rav Yehuda Henkin, does permit immersion in such cases for physical contact, though not for relations.

In some extreme cases, Rav Henkin would permit relations after performing a bedikah. If your mikveh night does fall out on your veset, please write back with more details about your condition and how long you will need to continue with this medication.

If your last period began during the day, and you are observing the night as an onat perishah out of stringency, then you may immerse and even have relations on that night. In such a case, you should perform a bedikah prior to relations.

It may be that some modification to your medication could help you lengthen your cycles. If you have not yet done so, please bring this consideration to the attention of your physician. For this purpose, you may find it helpful to refer your physician to the section of our website designed for healthcare professionals, Jewish Women’s Health, written to facilitate communication between women and their healthcare providers on niddah-related issues.

Please write back with any further questions.