At-Talaq 65:4

Walla-ee ya-isna mina almaheedimin nisa-ikum ini irtabtum faAAiddatuhunna thalathatuashhurin walla-ee lam yahidna waolatual-ahmali ajaluhunna an yadaAAna hamlahunnawaman yattaqi Allaha yajAAal lahu min amrihi yusra

And those who no longer expect menstruation among your women - if you doubt, then their period is three months, and [also for] those who have not menstruated. And for those who are pregnant, their term is until they give birth. And whoever fears Allāh - He will make for him of his matter ease.

And those women from among you who have despaired of (further) menstruation, if you are in doubt, their ‘Iddah is three months, as well as of those who have not yet menstruated. As for those having pregnancy, their term (of ‘Iddah ) is that they give birth to their child. And whoever fears Allah, He brings about ease for him in his affair.