Describe how the menstrual cycle would differ in phase 3 if the egg were fertilized?

If the egg is fertilized during phase 3 of the menstrual cycle, known as the luteal phase, the hormone progesterone continues to rise, supporting the uterine lining for potential implantation. Instead of degrading, the corpus luteum persists, producing hormones to maintain the endometrial lining and prevent menstruation. This phase transitions into early pregnancy, where human chorionic gonadotropin (hCG) is produced, signaling the body to sustain the pregnancy rather than prepare for the next cycle. Consequently, menstruation does not occur, and the cycle is effectively halted.