Irregular periods: possible causes and when to see a doctor

Periods that come after three weeks one month and after two months the next, a skipped cycle or unpredictable bleeding: many women experience irregular periods at some point. Often it is a temporary change. Sometimes it is a sign of a hormonal imbalance that is worth investigating, especially when you are trying for a baby.

This article explains what a normal cycle looks like, the possible causes of an irregular cycle, the tests your doctor may suggest and the situations that should lead you to book an appointment.

What is a normal cycle?

The menstrual cycle is counted from the first day of one period to the first day of the next. A cycle is generally considered regular when it lasts between about 21 and 35 days and varies little from month to month. Periods usually last 3 to 7 days.

A 28 day cycle is only an average: a perfectly stable 32 day cycle is completely normal. What matters is regularity over time and the absence of worrying symptoms.

Periods are described as irregular when:

• the cycle length changes a lot from one month to the next;
• cycles are very short or very long;
• periods stop for several months;
• bleeding happens between periods.

Possible causes

Times of transition

In the years after the first period, cycles are often irregular while ovulation becomes established. Likewise, as menopause approaches, cycles often become irregular before they stop. After childbirth and while breastfeeding, periods may also return irregularly.

Polycystic ovary syndrome

PCOS is a common cause of long, irregular cycles in young women. It often combines ovulation problems with acne, excess hair growth or weight gain. It is diagnosed through your history, an ultrasound scan and hormone tests.

Hormonal disorders

An overactive or underactive thyroid, a high prolactin level or other hormonal imbalances can disturb ovulation and therefore the cycle. A simple blood test often detects them.

Lifestyle

Major stress, rapid weight loss or gain, very intense sport, night shifts or travel can temporarily disrupt the cycle.

Medicines and contraception

Some hormonal contraceptives change the timing or heaviness of periods, especially in the first months or after stopping them. Other medicines can also affect the cycle.

Gynecological causes

A fibroid, an endometrial polyp or another abnormality of the uterus can cause irregular or heavy bleeding. Pregnancy, including early pregnancy, should always be considered when a period is late or bleeding is unusual.

When should you see a doctor?

Irregular periods are usually not an emergency, but some situations call for an appointment:

• no period for three months or more, outside pregnancy or breastfeeding;
• cycles regularly shorter than 21 days or longer than 35 days;
• bleeding between periods or after intercourse;
• very heavy periods, with clots or marked tiredness;
• unusual acne, hair growth or weight gain;
• difficulty getting pregnant.

If you have heavy bleeding with feeling faint, severe pain, or a positive pregnancy test with pain, seek care quickly. Our article when to see a gynecologist gives more useful guidance.

Tests your doctor may suggest

The consultation starts with detailed questions about your cycles, so it helps to write down for a few months the start and end dates of your periods, how heavy they are and any symptoms. An app or a simple calendar is enough.

Depending on the situation, your doctor may then suggest:

• a pregnancy test if a period is late;
• a pelvic ultrasound to look at the uterus and ovaries;
• hormone blood tests, sometimes on a specific day of the cycle;
• other tests depending on your symptoms.

Irregular periods and fertility

An irregular cycle often means that ovulation does not happen every month, or that it happens on dates that are hard to predict. Finding your fertile window becomes harder, and pregnancy may take longer.

The good news is that ovulation problems are among the causes of infertility that respond well to treatment. Depending on the cause, treating the thyroid, correcting prolactin, adjusting lifestyle or stimulating ovulation can restore the chances of pregnancy. If you are trying to conceive and your cycles are irregular, do not wait too long: a fertility assessment, described on our infertility page (page in French), helps the couple take stock.

Seeing a doctor in Fes for irregular periods

Are your cycles worrying you, do you no longer know when to expect your period, or is your pregnancy plan taking time? A consultation helps identify the cause and offer suitable care, which is often simple.

At Boudra Fertility Center, an IVF center in Fes, Dr Najib Boudra, a gynecologist with more than 30 years of experience, sees you in a gynecology consultation to review your cycle, with an ultrasound and tests if needed. Book an appointment on 05 35 93 08 18.

Frequently asked questions

This article is for information only and does not replace a consultation. For any question about your situation, talk to your doctor.