What Are the Phases of a Menstrual Cycle?

The menstrual cycle is said to last 28 days (but is often longer or shorter for different women) and can be broken up into four different phases. Each phase has different things going on, both physically and in terms of how your hormones are changing

A cycle is measured from the first day of your period. Like us, you might find popping a dot or symbol in your diary on that day will help you work out how long your cycle is. If it’s regular, it means you’ll be able to predict when your period will start and avoid any surprises!

Phase 1:

The first day of your cycle is measured from the first day of your period. Your period may last 2 – 7 days, with most fluid being lost in the first two days.

Phase 2:

Your period should have finished and your level of the hormone oestrogen is on the rise. An ovum (or egg) is ripening in a little bubble on an ovary while the lining of your uterus slowly begins to build up. During this phase, due to the oestrogen, your skin could be smoother, your breasts a little bigger and any discharge will be clear.

Phase 3:

The level of oestrogen peaks, causing the ovum to be released into the fallopian tube. This is called ovulation. You may feel slightly ‘bloated’ as this phase can trigger fluid retention throughout your body – but it’s not dangerous and doesn’t last.

Phase 4:

If the ovum has been fertilised it takes 5 to 7 days to travel to the uterus and embed itself into the lining and start growing. Of course, in most cases, it won’t be fertilised so it disintegrates within 48 hours and the high level of oestrogen, and another hormone called progesterone, drop sharply.

This sudden change can cause mood swings (also called PMS Pre-Menstrual Stress) and you may also experience cramps as the uterus contracts in readiness to shed the built-up layer – which takes you back to Phase 1; having your period.