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.
Since the questioner mentioned that her pregnancy was in its second month, the blood she found before the miscarriage was not the blood of menstruation because a pregnant woman does not experience menstruation according to the preponderant opinion of many people of knowledge including Imaam Ahmad . If the intended meaning of aborting the ovum is aborting the pregnancy, then the blood she found after the abortion is also not considered post partum bleeding because that occurs when a woman aborts a fetus that has the form of a human being.
Scholars mentioned that the least period for this is most probably eighty-one days. Therefore, this blood is attributed to Istihaadhah (i.e. vaginal bleeding outside the menstrual period) and illness and not to menstruation and post partum bleeding. The blood of Istihaadhah does not entail abandoning prayer, fasting and other matters that are forbidden for women when experiencing menstruation. She should not have broken her fast on these days unless it was due to illness. She should make up for these days in any case.
Allaah Knows best.