Contemporary authorities differ as to whether someone within 24 months after birth – who is defined halachically as a meineket, regardless of whether she is actually breastfeeding – can establish a veset kavua. The halachic authority for this site rules that a woman who has resumed menstruating postpartum can establish a veset kavua if she gets her period on the same date or interval three times in a row. She follows all the halachot of a woman with a veset kavua.

If your period started after 56 days on the same onah, night or day (or after 56 onot, if the online calendar is set to follow Chabad custom), 3 times in a row, then you have established a veset kavua, as per the message you received from your online mikvah calendar.

B'Hatzlacha!

This response was updated on 5 October, 2025.