What is the waiting period (iddah) for a divorced, menstruating woman who had agreed with her husband on contraception and was then divorced? And can she marry immediately after the divorce due to her womb being free of sperm?

If a woman experiences menstruation, she is obligated to observe an 'iddah (waiting period) of three quru' (menstrual cycles) after divorce. Her agreement with her husband to practice 'azl (coitus interruptus) does not nullify her 'iddah, due to the possibility of semen preceding withdrawal and conception occurring. Moreover, the cleansing of the womb is not the sole wisdom behind the 'iddah.