What is the ruling concerning the two days I did not fast in Ramadan due to bleeding after a miscarriage at four weeks, thinking it was menstruation or nifas (postpartum bleeding), based on the fatwa of Sheikh Ibn 'Uthaymeen which states that the bleeding is not considered nifas if the fetus is aborted before the third month?

The blood discharged with a miscarriage in the fourth week is not considered postpartum bleeding (nifas (definition)), because it does not yet show the formation of a human being. If it coincides with the days of the regular menstrual period, it is considered menstruation. There is no sin upon one who abstained from prayer and fasting, thinking it was nifas, but she must make up the prayers and fasts.