There is no one answer to this question as different orders of nuns have different policies and practices when it comes to dealing with periods. Some orders may require nuns to abstain from all physical activity during their period, while others may allow them to continue with their normal routine but take precautions such as wearing extra absorbent pads or tampons. Still other orders may have more lenient policies and simply ask that nuns use common sense and good hygiene when it comes to managing their periods.
In general, though, most nuns try to be as discreet as possible about their periods and avoid talking about it openly with others. This is partly out of a desire to maintain a sense of modesty, but also because many religious orders consider menstruation to be a symbol of impurity. As such, some nuns believe that it is best not to draw attention to it or make a big deal out of it.
That said, there are also many nun who are open and frank about their periods, and see nothing wrong with discussing it openly with others. For these women, menstruation is simply a natural part of life that should not be hidden away or treated as something shameful. No matter what their individual views on the matter may be, though, all nuns strive to approach menstruation in a respectful and dignified way.