2:222
وَ يَسْـَٔلُ ونَ كَ عَنِ ٱلْ مَحِيضِ قُلْ هُوَ أَذًى فَ ٱعْتَزِلُ وا۟ ٱل نِّسَآءَ فِى ٱلْ مَحِيضِ وَ لَا تَقْرَبُ و هُنَّ حَتَّىٰ يَطْهُرْ نَ فَ إِذَا تَطَهَّرْ نَ فَ أْتُ و هُنَّ مِنْ حَيْثُ أَمَرَ كُمُ ٱللَّهُ إِنَّ ٱللَّهَ يُحِبُّ ٱل تَّوَّٰبِينَ وَ يُحِبُّ ٱلْ مُتَطَهِّرِينَ
And they ask you about menstruation. Say, "It is harm, so keep away from wives during menstruation. And do not approach them until they are pure. And when they have purified themselves, then come to them from where Allah has ordained for you. Indeed, Allah loves those who are constantly repentant and loves those who purify themselves."
65:4
وَ ٱلَّٰٓـِٔى يَئِسْ نَ مِنَ ٱلْ مَحِيضِ مِن نِّسَآئِ كُمْ إِنِ ٱرْتَبْ تُمْ فَ عِدَّتُ هُنَّ ثَلَٰثَةُ أَشْهُرٍ وَ ٱلَّٰٓـِٔى لَمْ يَحِضْ نَ وَ أُو۟لَٰتُ ٱلْ أَحْمَالِ أَجَلُ هُنَّ أَن يَضَعْ نَ حَمْلَ هُنَّ وَ مَن يَتَّقِ ٱللَّهَ يَجْعَل لَّ هُۥ مِنْ أَمْرِ هِۦ يُسْرًا
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 Allah - He will make for him of his matter ease.