Menstruation
عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ عَبْدِ اللَّهِ بْنِ الْمُغِيرَةِ عَمَّنْ أَخْبَرَهُ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ إِذَا كَانَتْ أَيَّامُ الْمَرْأَةِ عَشَرَةَ أَيَّامٍ لَمْ تَسْتَظْهِرْ وَ إِذَا كَانَتْ أَقَلَّ اسْتَظْهَرَتْ
Ali Bin Ibrahim, from his father, from Abdullah Bin Al Mugheira, from the one who informed him,
(It has been narrated) from Abu Abdullah-asws having said: ‘When the (regular) days (of the menstruation (Haydh) of the woman are ten days, she would not examine herself, and when it was less, she should examine herself’.[1]
[1] Al Kafi – V 3 – The Book of Menstruation (Haydh) Ch 3 H 3