Is this cheating that I completed my prayer when my menstruation started during Fajr prayer?

The onset of menstruation during prayer invalidates it, based on the Prophet's (peace and blessings be upon him) saying: "Is it not true that when she menstruates, she neither prays nor fasts?" There is no need to make up the prayer during which menstruation began, nor any other prayers for the duration of the menstrual period. This is based on what was narrated from 'Aisha (may Allah be pleased with her) who said: "That would happen to us, and we would be commanded to make up the fasts, but we would not be commanded to make up the prayers."