Menstruation – Understand your cycle and get pregnant

Menstruation – a word that some associate with pain and hormones, which can affect mood for better or worse. But menstruation is also a sign that the body is functioning and that one is capable of having children.

Menstrual calculator – When will I get my next period?

You can calculate when your next period will start using our calculator below. Simply enter the date of your last period, how long your period usually lasts, and the typical length of your cycle.

Fill in the date of your last period, the usual number of days your period lasts, and the average length of your cycle. Then, you’ll get an estimate of when to expect your next period as well as your most fertile days for the coming 3 months.

What is menstruation?

Menstruation is a monthly bleeding process. It occurs because, after ovulation, the female body allows the lining of the uterus to grow, preparing it for a fertilized egg. If the egg is not fertilized after ovulation, the uterine lining is shed approximately two weeks later. This process is called menstruation.

Menstrual blood consists of the shed uterine lining and blood, and it usually lasts 3-5 days.

What is a normal menstrual cycle?

A menstrual cycle begins on the first day of your period and ends the day before your next period starts. The number of days from the first day of menstruation to the day before your next period starts is the length of your cycle.

How long does a menstrual cycle last?

The length of the menstrual cycle varies from person to person. On average, it lasts 28 days, but it’s completely normal for cycles to range between 23 and 35 days.

Phases of menstruation

A menstrual cycle typically consists of 4 phases:

● Menstruation

● The Follicular Phase

● Ovulation

● The Luteal Phase

You can read more about the menstrual cycle, its 4 phases, and how they impact the body and mood in our article here.

Read more about ovulation and try our ovulation calculator here.

How menstruation affects your mood

Most women know that mood and well-being can depend on where they are in their cycle. A large American study has shown how much the cycle can influence women’s mood.

The menstrual cycle has a greater impact on mood than factors like season, holidays, or weekdays. The study, based on data from 3.3 million women who logged mood and menstruation in an app, shows mood shifts at different cycle stages, due to hormonal changes.

Leading up to ovulation, estrogen dominates, boosting confidence and energy. After ovulation, estrogen drops, and progesterone rises, which has a calming effect and can bring on feelings of tiredness or sadness. When menstruation ends, estrogen rises again, and mood follows the cycle.

Read more about progesterone here.

Menstrual Pain

5-9 out of 10 women experience menstrual pain to some degree before or during menstruation. For 10% of women, the pain is so intense it results in a sick day from work or school.

Menstrual pain often feels like cramps in the pelvis, thighs, back, or abdomen. This pain arises because the uterus, a muscle, contracts to shed the lining and unfertilized egg. These contractions cause the pain known as menstrual cramps.

How can menstrual pain be relieved?

Pain relievers can ease menstrual pain. Exercise, like swimming, yoga, and pilates, can also help reduce discomfort. Many also find relief from using a warm compress or heating pad on the area.

Gentle exercises like swimming, yoga, and pilates can often alleviate menstrual pain.

Irregular menstruation

Menstruation is considered irregular if the time between periods or duration of bleeding varies significantly. Irregular bleeding is often due to hormonal imbalances. If your cycle is shorter than 21 days or longer than 35 days over multiple periods, you should consult your doctor. Read more about irregular and regular menstruation here.

It’s normal to have one irregular period per year, often due to weight changes, stress, new relationships, or other internal or external factors.

Common causes of irregular menstruation include:

● PCOS. Read more about PCOS here: What is PCOS? Symptoms, Causes, and Treatment.

● Thyroid issues

● Eating disorders

● Overweight

● Stress

● Cervical inflammation

● Chlamydia

● Polyps or fibroids

● Cellular changes

Regular menstruation

A completely regular menstrual cycle lasts an average of 28 days, but it’s normal for the duration to vary. The actual menstruation lasts 4-7 days, followed by about 3 weeks without menstruation until the next cycle starts.

Regular menstruation means the cycle and bleeding duration are relatively consistent each month.

Delayed Menstruation

The primary cause of a missed period is pregnancy. You can check with a pregnancy test. If you want to know more about when you can test for pregnancy, read our article here.

Find our selection of pregnancy tests here.

Delayed menstruation can also result from missed ovulation, often due to hormonal imbalances. Symptoms of hormonal imbalances include late, irregular, or missed periods.

Chronic stress or long-term anxiety can increase prolactin, which suppresses hormone production, resulting in delayed or missed periods.

Being overweight can create hormonal imbalances, leading to fewer or no ovulations and, therefore, delayed or absent periods. This also applies to underweight, intense exercise, or strict dieting.

New contraceptives, hormonal medications, or emergency contraception can affect the cycle by disrupting hormonal balance, taking time for the body to return to its natural rhythm.

Gynecological conditions like endometriosis and polycystic ovary syndrome (PCOS) can also cause delayed menstruation or an irregular cycle.

Missed or delayed menstruation can also result from reduced or absent ovulation due to various hormonal imbalances.

Read more about ovulation and calculate your ovulation here.

First Period After Miscarriage

You’ll typically get your period 4-8 weeks after a miscarriage, with an average of about 40 days. The timeline depends on the regularity and length of your cycle.

It may take time for hCG levels (pregnancy hormone) to leave the body after a miscarriage. Only then will ovulation, menstruation, and a normal cycle resume. Ovulation usually occurs within 2-6 weeks post-miscarriage; with an average cycle, menstruation arrives about two weeks later.

When menstruation returns, it indicates that your cycle has normalized. Generally, the further along the pregnancy was, the longer it takes for hCG to leave the body and for the cycle to normalize. This is also true if your cycle is typically long or irregular. Read more about regular and irregular cycles in our article here.

Menstruation after birth

After childbirth, there is postpartum bleeding from the area where the placenta was attached. This bleeding can last up to eight weeks. While it resembles menstruation, it doesn’t mean the body has resumed its cycle.

After the postpartum bleeding stops, menstruation may slowly return. This timing can vary, as it depends on when the body’s hormones stabilize. Menstruation can return as early as four weeks post-birth or up to a year and a half later. Breastfeeding plays a big role; the more one breastfeeds, the longer it can take for menstruation to return, as prolactin production suppresses ovulation.

Remember that ovulation occurs before menstruation. So, it’s possible to become pregnant before experiencing your first post-birth period. This is why contraception is often discussed at the 8-week postpartum check-up.

Frequently Asked Questions About Menstruation

What is menstruation, and why do women have it?

Menstruation is the monthly bleeding that occurs as part of the female cycle. Bleeding happens when the uterine lining is shed if no fertilization occurs, preparing the body for a new cycle and potential pregnancy.

When do you get your first period?

In Denmark, girls typically get their first period between 9 and 18, with an average age of 12.5.

When does menstruation stop?

Menstruation generally continues until menopause, between 45 and 55, with an average age of 52.

How long does a normal period last?

A period usually lasts 3-5 days, and the average cycle lasts 28 days.

What is PMS, and what causes it?

PMS (premenstrual syndrome) includes physical and emotional symptoms, like mood swings, bloating, and fatigue, occurring right before menstruation. It’s caused by hormonal changes, especially fluctuations in estrogen and progesterone.

Why is my period late?

A late period can be due to factors like stress, hormonal changes, weight changes, or intense exercise. It may also be an early sign of pregnancy. If your period is often irregular, it may be helpful to talk to a doctor.

Is it normal to have heavy periods?

Heavy periods are common, affecting 10-20% of women in Denmark. Causes are often benign hormonal imbalances, fibroids, and genetics. If it disrupts daily life or causes severe pain, it may be helpful to see a doctor for support.

Can you get pregnant during your period?

It’s unlikely, as menstruation falls in the non-fertile period of the cycle. However, there’s a small chance since sperm can survive in the body for up to five days. So, if you have a short cycle with early ovulation, pregnancy cannot be ruled out.

Source: Sundhed.dk, Sundhedsstyrelsen, Netdoktor.dk, Medicin.dk, Hvidovre Hospital, Nature.com