Why do menstruation occurs

Then the cycle begins all over again. If you have sex during a cycle, and your egg meets a sperm, you can become pregnant. The average cycle is 28 days but, for some women, it is as short as 21 days, for others it is as long as 35 days.

When you first start having periods, it can also take a while before your periods develop a regular pattern.

Your cycle also changes as you get older. Your menstruation cycle and period stops temporarily when you are pregnant. Breastfeeding also affects your cycle. At the end of menopause, your cycle stops permanently. Some women will have pain in their belly the lower abdomen. This can be a crampy pain or just a mild ache. You may have lower backache on its own or with the pain in your belly. The pain can often be stronger on the first day or two of your period and will vary in strength and severity from one women to another.

Some women also have a headache or feel very tired just before their period arrives or on the first day. But menopause can happen earlier or later. Some women may stop menstruation by the time they're 35 years old, and others may not stop until their late 50s. For a better experience on always. United English. Do you want to continue? Search for:. Bladder Leak Protection Leaks can't stop you now! What are Always FlexFoam pads made of? What are Always Liners made of? Use our period calculator.

Recommended Times Recommend. Any personal info you provide on the other site will be managed by their privacy policy. Share on. A woman is generally most likely to get pregnant fertile if she has sex a few days before, and during ovulation. Menstruation is one part of a woman's cycle when the lining of the uterus endometrium is shed.

This occurs throughout a woman's reproductive life. With each monthly cycle, the endometrium prepares itself to nourish a fetus. Increased levels of estrogen and progesterone help thicken its walls. If fertilization does not occur, the endometrium, along with blood and mucus from the vagina and cervix make up the menstrual flow that leaves the body through the vagina during the period.

On average, a young woman in the U. The uterus then sheds the lining which had grown to receive a fertilized egg. Your cycle uses hormonal signals as cues for what to do next. In the first part of your cycle, one of your ovaries prepares to release an egg. It also produces an increasing amount of the hormone estrogen.

This estrogen helps grow and prepare the lining of your uterus the endometrium for a potential pregnancy 1. After your ovary releases an egg ovulation , it produces the hormone progesterone. If an egg is fertilized, it then travels to the uterus over the next several days, implants in the uterine wall, and starts growing a hormone-producing placenta.

This drop in hormones prepares your endometrium to shed, and triggers the production of hormone-like prostaglandins , which cause your uterus to contract, causing your period 3, 4.

And the cycle starts again. In addition to the bleeding that happens during a period, some people also experience light, mid-cycle ovulation spotting. Periods fluctuate for a while after they first start.