For life-threatening medical emergencies, call 911 without delay. For a mental health crisis, call or text 988 for free and confidential crisis support.
During the follicular phase of the menstrual cycle, the lining of the uterus thickens. An egg becomes ready to be released inside a sac (follicle) on the surface of an ovary. During the luteal phase, the egg is released (ovulation). If the egg is fertilized by sperm, it may attach to the lining of the uterus (implant), and pregnancy begins. If the egg is not fertilized or a fertilized egg doesn't implant, the lining of the uterus is shed as blood during the menstrual period (below), and the cycle starts over.
Current as of:
April 18, 2023
Author: Healthwise Staff Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
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