(a) In the narration of Hisham bin Urwah: Shall I abandon the prayer? He (peace and blessings be upon him) said: "That is not menstruation; that is from a vein. When menstruation comes, abandon the prayer, and when it has gone, take a ritual bath and pray."
(b) This one is more likely to be the preserved version, because it agrees with the narration of the group, except that he said in it: "Take a ritual bath." (c) Ibn Uyaynah also narrated it with doubt. And Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1550