If she has fixed a Veset for 'Shaot' (Times) and not 'Yamim' (Days) she is only 'Choshesh' (concerned) for the hour - and this Veset is uprooted in one hour even without a 'Bedika' (check /physical examination)

MISHNA: If a woman was accustomed to see the flow of blood at the beginning of the sensation that accompanies her fixed cycle, even if on one occasion she happened to experience bleeding only at the end of the sensation, all the ritually pure items that she handled within the duration of that sensation that accompanies her fixed cycle are ritually impure. If the woman was accustomed to experience bleeding at the end of the sensation that accompanies her fixed cycle, all the ritually pure items that she handled within the duration of that sensation that accompanies her fixed cycle are pure.

Rabbi Yosei says: Even specific days and specific hours determine a fixed menstrual cycle: If a woman was accustomed to see the flow of blood on a certain day of the month at sunrise, it is prohibited for her to engage in intercourse with her husband only at sunrise; but during the night before and the following day, it is permitted for her to engage in intercourse. Rabbi Yehuda says: Once sunrise passed and she did not menstruate, the entire day is hers and she may engage in intercourse, in accordance with the opinion of Rabbi Yosei; but contrary to the opinion of Rabbi Yosei, intercourse the night before is prohibited.

GEMARA: A tannataught in a baraita: In what case did Rabbi Yosei say that specific days and hours determine a fixed menstrual cycle? For example, if a woman was accustomed to see the flow of blood on the twentieth day and again on the twentieth day, and in the sixth hour of the day and again in the sixth hour of the day the next time; if the twentieth day arrives a third time and she does not see a flow of blood, it is prohibited for her to engage in intercourse for the entirety of the first six hours of the day; this is the statement of Rabbi Yehuda. Rabbi Yosei deems it permitted for her to engage in intercourse until the sixth hour of the day, and says that she must be concerned only during the sixth hour.

Lorsque les époques surviennent par accident, le moment seul de l’accident est à appréhender; si l’accident est passé sans avoir produit l’effet attendu, il n’y a plus rien à craindre. Lorsque, par exemple, une femme de cette catégorie a aspiré fortement un peu avant le moment de ses époques, il faut qu’il y ait suspension de la vie intime dès cette aspiration pénible; mais si, ce moment passé, les époques ne sont pas venues, il n’y a plus rien à craindre. Si la femme a pour habitude d’avoir ses époques un certain temps après une aspiration pénible, elle doit se séparer de son mari, non au moment de cette respiration gênée, mais après, par crainte que l’indisposition ne survienne quelques heures plus tard. Il n’est question ici que du cas où les époques, survenant après une respiration gênée, se trouvent coïncider avec les époques habituelles; mais, si cette coïncidence n’a pas lieu exactement, il faut qu’après avoir senti sa respiration gênée, la femme se sépare de son mari, et qu’elle attende le moment de ses époques régulières.

If a woman usually observed her menstrual discharge at the onset of the symptoms of her regular periods, all clean things that she handled while the symptoms were in progress are unclean. But if she regularly observed them at the end of the symptoms, all clean things that she handled while the symptoms lasted remain clean. Rabbi Yose says: even days and hours may determine regular periods: if she regularly observed blood flow at sunrise she is forbidden intercourse at sunrise only. Rabbi Judah says: all that day is hers.

The Gemara relates another incident: There was a certain woman who came before Rabbi Yoḥanan and told him that every time she emerged from immersion in a ritual bath, after completing the mitzva of purifying herself for her husband, she would see blood before she engaged in intercourse with him. Rabbi Yoḥanan said to her: Perhaps the gossip of the women in your city, who are jealous of the love between you and your husband, has reached you, and this evil eye causes you to bleed before you engage in intercourse. Go and immerse in the river and engage in intercourse with your husband on the bank of the river, so that the other women will not see you leaving the ritual bath and gossip about you.

Some say that Rabbi Yoḥanan said to her: Reveal this fact to your friends, so that those women who were against you on this side, and gossiped about you, will be with you on that side, and be kind to you. And some say that Rabbi Yoḥanan said to her: Reveal this fact to your friends, in order that they will pray for mercy for you, as it is taught in a baraita discussing the verse: “And the leper in whom the mark is, his clothes shall be ripped and the hair of his head shall grow long and he will put a covering upon his upper lip and will cry: Impure, impure” (Leviticus 13:45). The leper publicizes the fact that he is ritually impure, as he must announce his pain to the masses, and then the masses will pray for mercy on his behalf.

Rav Yosef said: There was a similar incident in Pumbedita of a woman who experienced bleeding immediately after immersing in a ritual bath, and she followed the advice given by Rabbi Yoḥanan and she was cured.