Women’s menstrual cycles typically range from 21–35 days, counted from the first day of a period to the first day of the next one. Even if you are lucky enough to have a cycle that is regular and predictable, there will still likely be times when something throws it off. Below we explore some of the most common answers to the question, “Why is my period late?”

Pregnancy

Let’s start with the most obvious reason, which is pregnancy. A missed period is often the first inkling many women have that they are pregnant. If you’ve had sex in the past few weeks, even if you use birth control, this is the possibility you should investigate first. Most birth control options have some level of failure, even when used correctly. An over-the-counter pregnancy test is the easiest way to find out if this is the case.

It's important to note that IUDs have a small risk of ectopic pregnancy, which is when a fertilized egg implants outside of the uterus. This is a dangerous condition, so if you have a positive pregnancy test and have an IUD, consult your women’s health provider quickly.

Perimenopause

As women get closer to menopause, a period known as perimenopause, many find their periods become more irregular and unpredictable. Perimenopause can last from less than a year to as long as a decade. You may find your periods become heavier or lighter, or you skip some months and then have several close together. Although this is common, talk to your women’s health provider if you have questions or need help managing any of the signs of menopause, from irregular periods to hot flashes, mood swings or sleep issues.

Lifestyle Factors

Anything that affects your body’s ability to produce or regulate hormones can ultimately affect your menstrual cycle. This includes lifestyle considerations such as high stress or extreme exercise. For example, if you are training intensely for a marathon or another sporting event, you may find your period is late or absent during that time. Even something like a change in your schedule, such as jet lag, can impact the timing of your period.

Your weight can also impact your menstrual cycle. Obesity affects the regulation of the hormones estrogen and progesterone, which both play a role in menstruation. Similarly, if you are severely underweight, your body may lack the fat and nutrients it needs for regular hormone production. Rapid weight loss due to illness, crash dieting or other causes can also disrupt your body’s hormone production and result in a delayed or missed period.

Medications

If you have recently started taking a new medication, there is a possibility it may interfere with your menstrual cycle. The list includes birth control, antidepressants and antipsychotics, chemotherapy drugs and others. Check the possible side effects of your medications or talk to your prescribing doctor or pharmacist if you have any questions.

Health Conditions and Diseases

There are several chronic health conditions and diseases that can affect menstruation, such as:

·         Polycystic Ovary Syndrome (PCOS)

·         Primary Ovarian Insufficiency (POI)

·         Pituitary tumors

·         Diseases of the adrenal or thyroid glands

·         Ovarian cysts

·         Liver dysfunction

·         Diabetes

Acute health events—such as a heart attack, meningitis or pneumonia—can trigger disruptions to your cycle as well. If you have any other symptoms in addition to a late or missed period, schedule an appointment with your healthcare provider.

Here to Help

If you are concerned about a late or missed period, give us a call to talk to a provider or request an appointment. We can help determine the cause and recommend treatment if necessary.

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