Ruling on a woman who does not know the exact days she broke her fast due to her menstruation

Q: My menstrual period stopped and started again only ten days later. It continued for four days then I took medicine so it stopped. This happened during Ramadan in this current year 1400 A. H. The point is that I continued to observe Sawm (Fast) and combine Salah (Prayer) for the four days of the second menstruation mentioned above. Should I make up for these four days or it is sufficient that I fasted them in Ramadan bearing in mind that the blood was black in color during these four days? Please answer us. May Allah reward you with the best.

A: It is obligatory on you to perform Sawm for the four days mentioned. This is because the Sawm you performed for these days while you were bleeding was invalid as the black blood you have mentioned in the question was menstrual blood.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.