What are the phases of your menstrual cycle
By Juliana Kassianos, Transformational Fertility Coach, Yoga Teacher and Founder of The School of Fertility
The menstrual cycle starts on the first day of your period. The average menstrual cycle is 28 days long, but it can vary from 21 to 35 days. It is divided into four phases. For a 28 day cycle, this would be:
Days 1-5: Menstrual Phase
Days 1-13: Follicular Phase
Day 14: Ovulation Phase
Days 15-28: Luteal Phase
WHAT HORMONES ARE INVOLVED?
Hormones are chemical messengers. There are four main hormones involved in controlling your cycle.
Follicle Stimulating Hormone (FSH) produced by Pituitary gland (in brain)
Oestrogen produced by ovaries
Luteinising Hormone (LH) produced by Pituitary gland
Progesterone produced by ovaries
FSH signals for the eggs that are contained in little sacs called follicles to mature. Usually one matures faster than the others. FSH also stimulates the ovaries to produce oestrogen.
Oestrogen encourages the follicle to develop further and makes sure the uterus lining thickens ready for implantation of the egg.
A surge in LH stimulates ovulation. The mature egg is released from the follicle in the ovary into the fallopian tube.
The empty follicle turns into a corpus luteum and starts to produce progesterone, which causes the lining of the uterus to become even thicker. The muscles of the fallopian tube contract propelling the egg along. If the egg is fertilised in the fallopian tube, the embryo implants itself into the uterus lining and progesterone levels stay high. If the egg isn’t fertilised, levels of oestrogen and progesterone fall, causing the lining of the uterus to shed.