What are the rulings regarding taking birth control pills, with menstruation occurring for one week and then stopping for one week regularly?

All praise is due to Allah, and may peace and blessings be upon the Messenger of Allah. This is a clarification regarding the ruling on a woman experiencing irregular bleeding (istihada). The maximum duration of menstruation is fifteen days, and the minimum period of purity between two menstruations is thirteen days according to the Hanbalis, and fifteen days according to the majority of scholars. A woman experiencing irregular bleeding should refer to her previous habitual cycle if she knows it, or she should distinguish between menstrual blood and irregular bleeding by their characteristics. If she does not have a habit or cannot distinguish, she should consider herself menstruating for six or seven days, similar to the custom of the women in her family. After the menstrual period ends, she should perform ghusl (ritual bath), pray, and fast. She should perform wudu (ablution) for each prayer, while taking precautions to prevent the spread of impurity.