Purity: Duration of Ḥayḍ

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 438:

Ḥayḍ cannot last for less than three days or more than ten days; if bleeding lasts for even a little less than three days, it is not ḥayḍ.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)