Is a woman considered to have prolonged bleeding (istihada) if her menstrual cycle is irregular, the duration of her menstruation does not exceed 15 days, and the duration of her purity (tuhr) is often less than 13 days, and how is the time of prolonged bleeding (istihada) calculated in this case?

The minimum period of purity between two menstrual cycles is fifteen days according to the majority of scholars, and thirteen days according to the Hanbalis. If the bleeding recurs before this period elapses, it cannot be considered a new menstrual cycle; rather, it may be irregular bleeding (istihada) or a continuation of the previous menstrual period. The details of the irregular bleeding experienced by the questioner were not provided, making it difficult to rule on her specific case. It is advisable to directly consult scholars for clarification of the details.