Fatimah daughter of Abu Hubaish came to the Messenger of Allah ﷺ and said: I am a woman who has prolonged flow of blood; I am never purified ; should I abandon prayer ? He replied: This is (due to) a vein, and not menstruation. When the menstruation begins, you should abandon prayer ; when it is finished, you should wash away the blood and pray.
أَنَّ فَاطِمَةَ بِنْتَ أَبِي حُبَيْشٍ جَاءَتْ رَسُولَ اللَّهِ ﷺ فَقَالَتْ إِنِّي امْرَأَةٌ أُسْتَحَاضُ فَلاَ أَطْهُرُ أَفَأَدَعُ الصَّلاَةَ قَالَ إِنَّمَا ذَلِكِ عِرْقٌ وَلَيْسَتْ بِالْحَيْضَةِ فَإِذَا أَقْبَلَتِ الْحَيْضَةُ فَدَعِي الصَّلاَةَ وَإِذَا أَدْبَرَتْ فَاغْسِلِي عَنْكِ الدَّمَ ثُمَّ صَلِّي