The menstrual cycle occurs in the uterine endometrium.
It is the monthly release of blood and mucosal tissues from the uterine lining.
It is often referred to as a period or a monthly period since it happens once a month and is the most obvious phase of the menstrual cycle.
The typical menstrual cycle comprises two phases: follicular and luteal.
The growth of the preovulatory follicle dominates the follicular phase, leading to estrogen-stimulated endometrial expansion.
The corpus luteum generates progesterone during the luteal phase, which slows endometrial growth and determines endometrial receptivity.
Luteal phase:
The luteal phase of the menstrual cycle begins on Day 14 following ovulation and lasts until the first day of your menstruation (Day 1).
It is also known as the ovulatory phase or the premenstrual phase.
During the luteal Phase, the follicle that ruptured and released the egg (during ovulation) transforms into a small yellow lump or cyst known as the corpus luteum.
Progesterone and oestrogen are secreted by the corpus luteum, causing the uterine lining, or endometrium, to thicken and become capable of maintaining a fertilised egg.
When sperm fertilises an egg, the embryo travels via the fallopian tube and eventually implants in the uterus.
Human chorionic gonadotropin (HCG) production begins in the early embryo, which supports the corpus luteum and progesterone production.
Until the placenta develops, the corpus luteum will support the uterine lining and pregnancy.