Thank you for reaching out to us.
Your first step is to see if you can reconstruct when your last flows began based on your mikveh dates. If you have the mikveh dates and there was no delay or disruption of the
clean days, then a week earlier was the day of the
hefsek taharah. Then, you can see if you can remember what day from bleeding the
hefsek taharah was (e.g., on day five or six) and work that out on the calendar.
If you can reconstruct both dates, that is ideal. If you can only reconstruct your most recent date, that is sufficient to determine your
onah beinonit and
veset hachodesh.
If you cannot reconstruct anything, then you would not observe
onot this month, but you should be especially cautious about having relations when you have any indication that bleeding is coming.
In addition to your
veset calendar, you might also find it helpful to keep some type of basic record on your phone of the days on which your flows begin.
Please let us know if we can be of further assistance.
