In order for a
veset kavua for a given interval to be uprooted, the
veset day has to pass without a bloodflow or a bloody
bedikah for three consecutive cycles. We do not usually base
vesatot on
bedikah cloths, but a bloody one means that the day is not uprooted.
The first cycle: Assuming you had bleeding on day thirty-three the first month, the first month did not in any way uproot your
veset kavua, even though the bleeding began earlier.
The second cycle: If you had no bloodflow and no bloody
bedikot on day thirty-three of the second cycle, then you did have one act of uprooting towards the three needed to uproot a
veset kavua.
The third (most recent) cycle: If you found blood on a
bedikah cloth on day thirty-three this past cycle, it did not uproot your
veset kavua in any way and cancelled any uprooting from cycle two. But if you only had
staining that didn't make you niddah on day thirty-three this past cycle, it could count as a second instance of uprooting. Even in this case, you would still have your
veset kavua (for now).
When a woman has a
veset kavua for
interval, if the interval changes, she is required to observe the new interval day in addition to the old one. The interval is assessed from the beginning of a flow, not from staining. So this coming cycle, you will observe night thirty-four as a
veset she-aino kavua.
(Note: Normally, the
yom hachodesh would also be observed as a
veset she-aino kavua. In this case, since you have established a consistent pattern of menses at intervals longer than one month, you need not observe
yom hachodesh.)
To summarize: You still have a
veset kavua for day thirty-three. In addition to your
veset kavua, you will also observe night thirty-four as a
veset she-aino kavua this coming cycle.
Please get back to us with any further questions.