Ata (may Allah have mercy on him) said: It was the opinion of Sayyida Aisha (may Allah be pleased with her) regarding a garment stained with menstrual blood that a woman should rub it on a stone, or rub it with wood or horn, then sprinkle water on it.
Hadith Referenceسنن دارمي / من كتاب الطهارة / 1057
Hadith Takhrijاس اثر کی سند صحیح ہے۔ دیکھئے: [مصنف عبدالرزاق 1228]
Brief Explanation
(Commentary on Ahadith 1042 to 1057)
From all these traditions and ahadith, it is understood that if a woman, during her menstrual period (hayd), gets blood on the clothes she is wearing, she may clean it and then pray in those clothes; there is no harm in this.