Umm Jahdar al-Amiriyyah (may Allah be pleased with her) asked Aishah (may Allah be pleased with her) about menstrual blood getting on a garment. Aishah (may Allah be pleased with her) said: I was with the Prophet (peace and blessings be upon him), and we had our undergarments on, and over them we had wrapped ourselves in cloaks. In the morning the Prophet (peace and blessings be upon him) took that cloak and wrapped himself in it, then he (peace and blessings be upon him) led the morning prayer. A man said: O Prophet of Allah! Its colour has changed because of blood? He (peace and blessings be upon him) gathered up the cloth from that place and sent it to me in the hand of a boy, and said: "Wash this, dry it, and send it back to me." Aishah (may Allah be pleased with her) said: I called for water in a bowl, washed it, dried it and sent it back to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) came at midday wearing that same cloth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4092