If the woman menstruates, her `iddah is three complete menstrual periods after the divorce, i.e., her period comes then she becomes pure, then her period comes again and she becomes pure, then her period comes again and she becomes pure. That is three complete menstrual periods. Almighty Allah says, “And divorced women shall wait for three menstrual periods.”[Al-Baqarah 2:228]. So, she has to wait until the end of the third period.