Is this drop of menstrual blood considered استحاضة (bleeding outside the regular menses) which necessitates prayer, or is it menstruation which prohibits prayer, and what should I do regarding the prayers I performed without performing ghusl (ritual purification)?

Scholars have differed regarding a single drop of blood being considered menses if it is followed by a cessation of blood. The majority of scholars hold that it is not considered menses because it is less than their minimum duration for menses, and they consider it istihadah (non-menstrual bleeding). As for the Malikis, they consider it menses because it falls within the minimum amount for menses, and they do not set a minimum time limit for menses.

The preponderant view is that of the majority of scholars for several reasons: 1. Linguistic aspect: Linguistically, hayd (menses) means the flow of something, and this description does not apply to a mere drop of blood. 2. Tradition (Athar): What was narrated from Ali ibn Abi Talib, may Allah be pleased with him, is that if a woman sees, after purification, something like the washing of meat or a drop, she should sprinkle water and pray and not perform ghusl, unless she sees thick blood. 3. Precaution for worship (Ihtiyat lil-'ibadah): Precaution dictates not considering this drop as menses, for certainty is not removed except by certainty, and most scholars do not consider it menses.

Based on this, this drop of blood is not menses but rather blood of corruption (dam fasad). Therefore, it does not prevent prayer or fasting and does not necessitate ghusl; rather, it only requires cleaning the area and performing ablution (wudu').