If your
veset is during the day, i.e. 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.
If your
veset is at night, then you are correct that 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
halachic supervisor permit immersion in this case, in order to allow husband and wife to enjoy
other forms of closeness short of relations.
This response was updated 15 December, 2025.