What should I do about making up the days I missed in Ramadan due to prolonged menstruation, given that I don't know the exact number of days I fasted, and will Allah accept what I have fasted after the next Ramadan begins?

Determining menstruation days from non-menstruation days is based on the duration of the cycle. If it lasts fifteen days or less, it is considered menstruation. If it exceeds fifteen days, it is considered istihadah (non-menstrual vaginal bleeding).

The jurisprudential schools (madhahib) differ regarding considering an increase beyond the usual period: - Shafi'is: They consider all bleeding as menstruation, even if it exceeds the usual period, relying on distinguishing between black blood and other types. If there is no distinction, the usual period is the reference. - Hanbalis: They consider an increase beyond the usual period as istihadah until the increase occurs three times, at which point menstruation is considered to have shifted. They refer to the usual period for determining the days of menstruation.

If the questioner fasted days that were possibly menstrual and wishes to make them up but does not know the number of days, it is sufficient for her to fast what she believes is most likely to absolve her responsibility. If the delay in making up the fasts was due to an excuse or ignorance, there is no expiation (kaffarah) upon her. The acceptance of fasting is known only to Allah the Almighty. There is no harm in adopting either of the two schools of thought.