Reasons for Missed Period When You’re Not Pregnant

If your period is late, the first thing that likely comes to mind is that you’re pregnant. In fact, missing a period, for most women, is often the first sign they see of pregnancy. But there can be other reasons for a late period besides being pregnant.

Typical Menstrual Cycles

As a rule, you may expect to have between 11 and 13 menstrual periods each year. This is assuming you have a menstrual cycle that is regular. Average periods have between three and five days, but they can be longer or shorter for some women. Normally, they last no longer than one week.

The menstrual cycle is thought to last 28 days, but it’s quite common for women of adult age to have cycles that range between 21 and 35 days. The first few years of periods for teenagers may show longer menstrual cycles. They vary in length from 21 to 45 days and are still considered normal for that age period.

Since cycles vary, you may have a period that is outside 35 days, and there is usually no cause for worry. As long as you still have a period each month, things are probably working as they should. If your cycle is more than 40 days, you may want to speak with your gynecologist to see if there is a reason for it.

Causes of Missed Periods

Most abnormal periods or missed periods are benign, and nothing is seriously wrong. It’s even normal to have occasional missed periods. Unless you miss two or three periods, your healthcare provider may not even be able to answer questions about the cause, without extensive testing.

No Ovulation

Lack of ovulation is the most common reason why you may miss your period. If you are trying to become pregnant and are not succeeding, you may not be ovulating. This can be caused by many variables.

Weight Issues

If you lose a large amount of weight, or gain weight rapidly, this can lead to missed periods, even when you are not pregnant. These are common causes for late periods and missed periods. If you’re thin, your body may not have a sufficient production of estrogen, which may cause you to have late or missed periods.

If you are overweight, you have too many fat cells in your body, causing it to over-produce estrogen. This is, in effect, much like taking a birth control pill, since that’s how your body reacts to it. You may not ovulate during each month, which means you will miss periods.

Anxiety and Stress

It’s hard to live in the world we have today without becoming stressed out. Stress is not good for your body, and it affects your cardiovascular system, immune system and menstrual cycles.

Since your cycles are regulated by the complex and delicate balance of your body’s hormones, something that alters hormone release will affect your periods, too. Stress can interfere with the command center of your brain, the hypothalamus, which produces hormones that regulate everything from your menstrual cycle to your emotions, sex drive and moods.

The process is complicated, but when the body is stressed, it disrupts all the processes of your body. Your mind perceives a threat and all the normal functions of the body, like menstrual cycles, are thrown off.


If you have just had a child and you’re breastfeeding, this interferes with regular periods. If you are giving your baby all his nutrition from breast milk, you normally will not have regular periods at all until that is done.

About 80% of women who bottle feed will experience the return of periods in roughly 10 weeks after delivery. Breastfeeding delays that, since your hormones are working to produce milk.


If you take birth control pills that affect the hormones of your body, you may have light periods or no periods. If you are on contraceptives and you still miss a period, it is unlikely that you are pregnant. You can take a home pregnancy test if you like, but these are not as accurate as checking with your OB-Gyn.

If you are on a newer birth control medication like Yaz, Seasonale or other brand names, these drugs change the regularity of your menstrual cycle. Missing periods is a fairly common occurrence when you take hormonal contraceptives.

Extended cycle contraceptives give you active hormone doses each day. These medications will stop your periods for an indefinite period of time, since they are ovulation inhibitors. The reasoning is quite logical – if you don’t ovulate, then you won’t have periods, so that you won’t get pregnant. Some of these medications can cause spotting or breakthrough bleeding.

Some extended cycle medications still leave you with periods, but you won’t have them as often. You may have as few as four periods a year. Bleeding and spotting between your periods are common in these prescription medications, too.

When you cease your use of birth control medications, it may take months for you to become fertile once again. This is due to the fact that your body needs to readjust to being without the medications. You may become fertile in just a couple months, but for many people, it does take longer for the female body to adjust to its normal levels of hormones.

It may take months for your ovulation and menstruation to return to their normal levels. It is reasonable to expect some missed periods during that transition.

Other types of birth control, like Depo-Provera, which is given in injection form, as well as birth control implants like Nexplanon or Implanon may lead to missed or irregular periods.

Eating Disorders

If you have an eating disorder, this is a dangerous condition that can even be life-threatening. It affects your whole body, including your menstrual cycles. If you plan to have children in the future, bulimia or anorexia can make it highly improbable that you will have a healthy pregnancy.

Non-Cancerous Pituitary Tumors

Tumor may be a scary word, but most tumors in the pituitary gland are benign, meaning that they are not cancerous. However, in this gland, they will affect the production of hormones when it’s time for a menstrual cycle. These tumors may cause missed or irregular periods if you are in the stage of early menopause known as peri-menopause.

Tumors in the pituitary gland cause it to produce high levels of prolactin, which normally stimulate the production of milk after birth. However, even if you’re not pregnant, your body still produces prolactin.

High levels of this hormone in your body may interfere with the proper functioning of your ovaries. This causes low estrogen levels, which in turn lead to irregular periods, missed periods and even infertility.

Hormonal Imbalances

As mentioned above, there is a fine interaction of hormones that lead to proper menstrual cycles. From the brain to the glands and organs, the hormones related to ovulation are critical. Your ovaries will not produce enough estrogen without the presence of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Many hormones work together to create proper ovulation and a period each month.

If something is amiss in this hormonal orchestra, and your hormones are not balanced, it screws up the menstrual cycle. As an example, if you don’t have an LH surge that helps a mature egg to erupt from follicles, you won’t ovulate and you’ll miss your period that month. An over-abundance of estrogen can also cause missed periods.


Some medicines disrupt your normal menstrual cycles. These include oral steroids, anti-psychotic drugs, anti-depressants and some drugs used in chemotherapy. They may cause you to have late or missed periods, or even no periods.

Vigorous Exercise

If you participate in sports and activities that require you to train rigorously, you may experience missed periods or have no periods. When you expend a great deal of energy, it stresses the body. In addition, lower body weight may also lead to missed periods due to no occurrence of ovulation.

Early Menopause and Peri-Menopause

Menopause is common for every woman, and it usually begins between the ages of 45 & 55. Menopause means that your reproductive life has ended. You won’t have periods anymore, and you will no longer be able to bear children.
Menopause is gradual. You won’t suddenly stop having any periods. The first phase is peri-menopause, and this starts a few years before conventional menopause begins.

Your transition from fertile to menopausal may take just a couple years, or it could take as long as 10 years. The average transition takes roughly four years, although this varies from one woman to the next. Sometimes your physician may even find it difficult to tell when you are in your transition to menopause.

Your ovaries begin producing less estrogen when you enter peri-menopause. This can cause irregular periods, along with other typical menopause symptoms like decreased sex drive and hot flashes. You may also experience more severe PMS symptoms.

You would expect that your periods would become lighter during your pre-menopausal months or years. This is not the case. You may have a horribly heavy period followed by a light one. Your periods may even become closer together. On the other hand, you may also miss periods.

If you miss a period and you’re 40-something, don’t assume that it is due to peri-menopause. You can still become pregnant in your 40’s, so use a home pregnancy test or check with your OB-Gyn, to make sure you’re not pregnant.

If you’re not 40 yet but you experience peri-menopausal symptoms, or irregular menstrual cycles, you may be entering early menopause. This can be brought on by surgeries on the reproductive organs, but it may also occur without any obvious cause.

Scarring of the Uterus

If medical procedures or disease have left your uterus scarred, this may prevent the usual build-up and sloughing of the lining of your uterus, which is the common menstrual cycle.

In cases like this, you may have lighter periods, or none at all. Your uterus may become scarred after uterine fibroid treatment, a D&C, a C-section or other health complications.

Jet lag from Travel

Even if you are normally quite regular in your menstrual cycles, traveling and especially jet lag can throw that cycle off its proper timing. Traveling is enjoyable, but it does come with stress, especially if you’re flying.

From all the preparation for the trip to the actual flight or drive or cruise, remembering what you’ll be doing and where you’ll be going can wreak havoc on your menstrual cycle. In addition, as a traveller you probably will have different than normal eating habits. Indulging in foreign culinary delicacies can throw off your system.

When you travel, your physical activity and exercise level will usually change. You may work out at home but not have time for it while on vacation. Or, if you do less exercising at home, travel may be an intense effort for your body. These lifestyle changes, even though they are temporary, can have an effect on your menstrual cycles.

Jet lag is a contributing factor to late periods, too. A new sleep schedule affects the way your body systems function. As a matter of fact, flight attendants in studies have been shown to have irregular cycles due to their circadian rhythms changing and also due to jet lag.

Thyroid Problems

An underactive thyroid gland, known as hypothyroidism, can cause missed periods and irregular menstruation. This may alter the amount of the hormone prolactin produced by your body, which then affects your normal cycle.

If your thyroid gland is overactive, a condition known as hyperthyroidism, it may cause you to have infrequent or light periods.

Coping with Missed Periods

If you missed a period but it’s only late by a week, don’t become stressed out about it. It could just be a late period. Take a home pregnancy test when you first notice that your period hasn’t started. You can take another in about a week’s time, since the hormone levels can predict pregnancy more accurately after one week.

Visit your physician if you’re concerned that you’re pregnant, even if your home tests came back negative. Your doctor has much more sophisticated testing methods available.

The treatment for late or missed periods depends on what caused you to miss your period. Medications can be prescribed, and lifestyle changes may be recommended.

The main point is not to let yourself become stressed out when you miss a period. It does happen now and then. Your period will likely return the following month.