Purity: Uncertainty Between Wound and Ḥayḍ

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 444:

If a woman experiences bleeding but does not know whether it is from a wound or due to ḥayḍ, she must perform her ritual acts of worship (ʿibādāt) [as normal], unless prior to this she was in the state of ḥayḍ [in which case she would consider it to be ḥayḍ].

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