All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Your ‘Umrah is valid – Allaah Willing –because the blood you saw was neither menses nor post-partum bleeding. It was not menses because the pregnant woman does not have menstruation and that is the opinion that we adopt, contrary to Maalik and Ash-Shaafi‘i. It was not a post-partum bleeding because the miscarried fetus had not taken the shape of a human, and the opinion of the majority of scholars is that if the miscarried fetus has not taken the shape of a human, the blood the woman suffers will be considered irregular bleeding.
As long as this blood was neither menses nor post-partum bleeding, it would be irregular bleeding, i.e. vaginal bleeding outside the menstrual period. Tawaaf is valid with the presence of that blood. Also, you have done what is required of you when you used to make Ghusl after its discharge and this was sufficient. It was narrated on the authority of Abu Az-Zubayr Al-Makki that Abu Maa‘iz ‘Abdullaah ibn Sufyaan told him that while he was sitting with Abdullaah ibn ‘Umar a woman came and asked: "I set out intending to make Tawaaf at the House, but then, when I got to the gate of the Mosque, I started bleeding, so I went back until it ended. Then I set out again, and then, when I got to the gate of the Mosque, I started bleeding, so I went back until it ended." ‘Abdullaah ibn ‘Umar said: "That is only an impulse from the devil. Make Ghusl, then bind your private parts with a piece of cloth and make Tawaaf." [Maalik]
Allaah Knows best.