O Prophet, when you divorce women, divorce them when they have reached their period. Count the period, and fear God your Lord. Do not expel them from their houses, nor let them go forth, except when they commit a flagrant indecency. Those are God's bounds; whosoever trespasses the bounds of God has done wrong to himself. Thou knowest not, perchance after that God will bring something new to pass
As for your women who have despaired of further menstruating, if you are in doubt, their period shall be three months; and those who have not menstruated as yet. And those who are with child, their term is when they bring forth their burden. Whoso fears God, God will appoint for him, of His command, easiness. S. 65:1, 4 Arberry
And those of your women as have passed the age of monthly courses, for them the 'Iddah (prescribed period), if you have doubts (about their periods), is three months, and for those who have no courses (i.e. they are still immature) their 'Iddah (prescribed period) is three months likewise, except in case of death]. And for those who are pregnant (whether they are divorced or their husbands are dead), their 'Iddah (prescribed period) is until they deliver (their burdens), and whosoever fears Allâh and keeps his duty to Him, He will make his matter easy for him. S. 65:4 Hilal-Khan