If a girl has period and remains clean for 12 days then she has period for 7 days. So how many days are haidh and how many istihaza?
In the name of Allah, Most Gracious, Most Merciful
The Prophet of Allah Sallallahu Alahi Wasalam has said, “Two menstruations cannot occur within fifteen days of each other.” (Sunan Baihaqi)
Keeping this hadith in mind your haidh will be four days and the three days before the fifteen days will be considered as istihadah.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham