Chapter 155 – Separation Before the Menstrual Term
155.1) A woman should separate herself from her husband the day before her flow begins (an onah “either a day or a night”).
155.2) Some define an onah as twenty-four hours.
155.3) A woman who has a thirty-day, intervening period between menstruations is considered to have regular menstruations.
155.4) When a woman perceives blood, she must suspect that she may perceive it again on the same date at the same time.
155.5) Examples are given of a woman who does not have regular periods here.
155.6) Examples are given of a woman who has regular periods here.
155.7) In the event a woman has no regular period, a husband should write down the day and the date of the month she has a perceived flow and the number of days of the flow to determine her unclean days. See the source for details.
155.8) The regular schedule may be changed when a regular period is not perceived as previously recorded. (See source for details, or consult a rabbi.)
155.9) The test for determining if menses are present is to insert cotton.
155.10) The principal day of menses is considered the day on which she begins to perceive blood.
155.11) One deviated occurrence of a menstrual flow abolishes the established time.
155.12) A woman three months pregnant need not be concerned about her periods or menstrual uncleanness.