First Time Haidh

1. A girl experiences her first bleeding. If it is 10 days or less, then all the days are of haidh.
2. If the bleeding continues for more than 10 days, then 10 days are of haidh and the rest istihaadhah.
3. If the bleeding did not stop upon 10 days and continued for some weeks or months then her haidh is 10 days from the beginning of the bleeding, and 20 days istihaadhah.
4. In this manner she should determine her haidh (that is 10 days haidh and 20 days istihaadhah), as long as the bleeding continues.

(Behshti Zewar)