I say, and with God's success: It is considered menstrual blood; because it has reached three days, and it does not matter if it stops within it. However, if it stopped in the previous case before the second emergence for a short time and the blood did not connect with it, and she did not see blood until the completion of fifteen days, it would not be considered menstruation. But if it returned before completing fifteen days from the time of cessation, such as returning on the tenth day or earlier, then all of it would be menstruation. If it returned later, then only the ten days would be menstruation, or the days of the habit only if she is accustomed; because incomplete purity is like continuous blood. Refer to: Dhakhr Al-Mutahhilin and Manhal Al-Waridin, pages 41-42, and others. And God knows best.