She is one of those with menstrual cycles (dhawat al-quru'), remaining upon her habit, thus she is similar to one whose menstruation did not experience a long interval. We know of no one who disagrees regarding this.

Section: Regarding the 'idda of the woman experiencing irregular bleeding (mustahada); it is either the case that she has a menstruation determined by habit or discrimination (tamyiz), or she does not. If she has a menstruation determined by these, her ruling is the same as the one who is not experiencing irregular bleeding; once three menstrual cycles have passed for her, her 'idda has terminated. Ahmad said: The mustahada observes 'idda for the days of her periods that she used to recognize. If she knows that she has one menstruation every month, but does not know its timing, her 'idda is three months. If she is in doubt about anything, she waits until she is certain that the three menstrual cycles have passed. If she is a beginner (mubtada'a) who has no discrimination, or is forgetful and does not know a time or discrimination for herself, there are two narrations from Ahmad regarding her. One of them is that her 'idda is three months; this is the opinion of 'Ikrimah, Qatadah, and Abu 'Ubayd, because the Prophet (peace be upon him) commanded Hamnah bint Jahsh to sit for six or seven days in every month. Thus, he established for her a menstruation in every month in which she leaves prayer and fasting, and all other rulings of menstruation are established for her; therefore, the 'idda must terminate by this, because that is among the rulings of menstruation. The second narration is that she observes an 'idda of a year, in the position of one whose menstruation has ceased and she does not know what caused it to cease. Ahmad said: If she has become confused and does not know the coming or going of the blood, she observes an 'idda of a year, based on the hadith of 'Umar, because by it pregnancy becomes clear. This is the opinion of Malik and Ishaq, because she did not attain certainty regarding her