Qur'an 65:4 · At-Talaaq

وَٱلَّٰٓـِٔى يَئِسْنَ مِنَ ٱلْمَحِيضِ مِن نِّسَآئِكُمْ إِنِ ٱرْتَبْتُمْ فَعِدَّتُهُنَّ ثَلَٰثَةُ أَشْهُرٍۢ وَٱلَّٰٓـِٔى لَمْ يَحِضْنَ ۚ وَأُو۟لَٰتُ ٱلْأَحْمَالِ أَجَلُهُنَّ أَن يَضَعْنَ حَمْلَهُنَّ ۚ وَمَن يَتَّقِ ٱللَّهَ يَجْعَل لَّهُۥ مِنْ أَمْرِهِۦ يُسْرًۭا

(4) 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.[1700] And whoever fears Allāh - He will make for him of his matter ease.