Does the spotting of blood resulting from the use of birth control pills invalidate Umrah if it occurs during its rituals?

Menstruation does not invalidate 'Umrah; rather, it prevents the menstruating woman from performing ṭawāf until she becomes pure, based on the Prophet’s saying to 'Aishah: "Perform all the rituals of Ḥajj except for circumambulating the House until you become pure." If she enters into iḥrām for 'Umrah, she waits until she becomes pure to complete her rituals. If she menstruates after ṭawāf, she completes the rituals, and there is no blame on her. As for drops of blood after the days of menstruation have ended: if they occur within the fifteen-day period (the maximum duration of menstruation), they are considered menstruation. If they occur after that period, they are considered istiḥāḍah (non-menstrual vaginal bleeding), for which ablution is required for every prayer.