Unexpected Pregnancy… or Not? 5 Reasons for a Missed Period & Negative Pregnancy Test

Written by: Clearway Staff 

Your period was supposed to come a week ago, but the days have come and gone with no sign of a period in sight. You start getting nervous. Does this mean a pregnancy decision is ahead of you? You weren’t planning on getting pregnant right now… what could you do with an unplanned pregnancy? Your mind starts running down the list: telling your partner and family, budgeting for a baby, health concerns, or any other such considerations that come with an unexpected pregnancy. There are options in front of you: abortion, adoption, parenting. Each brings up its own set of feelings and emotions in you. What to do? It’s a lot to think about. 

But then, you take a pregnancy test. It’s negative. A moment of relief is then followed by a moment of confusion. Then why haven’t I started my period?? 

There are many possible reasons for a missed period besides pregnancy. This article will explore five common ones.

Trigger Warning: The topic of eating disorders is discussed in this article.

Why Should I Care About Getting my Period?

When I was 17, I lost my period for almost a year. To be honest, I wasn’t upset about it. Periods are annoying anyway, I thought, and it made my life way easier not having to deal with cramps and bleeding every month. What I didn’t know at the time was that my lack of a period (not caused by pregnancy) was an indicator of other possible issues leading to hormonal imbalances in my body. 

Amenorrhea is the term used to describe the absence of menstruation, or no period. There is primary amenorrhea, which means someone is 15 years old and has still never had a period. There is also secondary amenorrhea, which is the absence of 3 or more periods (in a row) for someone who has had periods in the past. 

Often, amenorrhea can point to hormonal imbalances in your body (when it isn’t caused by pregnancy). Paying attention to your menstruation–or lack of it–can help you notice if your hormones become out of balance. 

Basically, it’s like this: the rhythm of your period is a reflection of other rhythms in your body. If your periods are irregular, that’s an indicator that something else is out of rhythm in your body (1). (Note: Some variation in your period is normal. Many people have irregular periods. Pay attention to your body and talk to your doctor if you are concerned about the regularity of your cycle. The information in this article is not a substitute for advice from a medical professional.) 

Although there are many possibilities of what could be going on, let’s review some common ones.

1. Stress

As human beings, we are integrated creatures. This means that things that happen to us in the emotional or psychological realm are not disconnected from our physical body. People under stress may experience chest pains, high blood pressure, back pain, headaches, and/or many other unpleasant symptoms. Even if your source of stress isn’t inherently physical, it can have physical consequences. Lost periods are one possible way your body can tell you you’re under too much stress.

Your period is regulated by the rise and fall of various hormones in your body. Your brain and your ovaries send messages back and forth. Different glands in your brain trigger the release of certain hormones, and your ovaries respond by creating others. 

When it comes to your cycle, first the follicular stimulating hormone rises, which tells your ovaries to get an egg ready and mature for ovulation. Then, when it’s the right time, the luteinizing hormone tells your ovary to release that mature egg. Estrogen rises to tell the uterus to thicken its lining, in preparation for the egg to be fertilized. Progesterone helps the uterus maintain that lining. When the egg is not fertilized, progesterone and estrogen levels fall, which causes your period. And your cycle begins again (2). 

What does this mean? Basically, between your brain and your ovaries, good communication is essential to keep your cycles regular. 

So what happens when stress enters the picture? Well, stress triggers the release of another hormone–cortisol–in our body. Cortisol is the hormone that puts our bodies into “fight-or-flight” mode, and its purpose is to help us survive in the face of danger. Cortisol talks to the brain, just like the other hormones do. And what does it say? Well, it tells the hypothalamus to stop producing hormones that give you your period. 

Now, this makes sense, biologically. When your physical survival is threatened, it’s not the best time to get pregnant. The release of cortisol is our body’s way of protecting us. But much of our stress is not life-threatening. Often, it’s emotional or psychological–a hard boss, a difficult relationship, demanding children, financial burdens, or even just a busy schedule. These types of stress still lead to the release of cortisol, and your lack of a period might be your body saying, “You’re too stressed!”

If you have been under a lot of pressure lately, don’t ignore the signs from your body. Even if you are still getting your period, stress can also impact your period symptoms and increase period pain. Talk to someone who will listen to you and can help you find the support you need. Call you health insurance provider to find out if they offer coverage for professional mental health counseling. If you are concerned about your painful periods, talk to a trusted medical professional. 

2. Birth Control

Various birth control methods can impact your period. Birth control can make your period longer, shorter, heavier, lighter, more frequent, or less frequent. Sometimes, contraception is used as a means to artificially regulate your period. Inconsistent periods are common among women using long-acting, progestin-based methods, such as various brands of implanted and ingested contraceptives. After a year of having an implant, about 50% of women will have no periods (3). Progestin IUDs can also lead to lighter or no periods, and emergency contraceptives (Plan B pills) can cause your period to come sooner or later than usual. 

Every woman’s body reacts to birth control differently. Make sure you are in conversation with your clinician about your chosen birth control method and if it is having any unexpected or abnormal impacts on your health. 

Different forms of birth control can impact the regularity of your period.

3. An Early Pregnancy

Pregnancy tests measure the hCG hormone levels in your urine. hCG hormones are present with a pregnancy, but it takes a few weeks for them to rise to any detectable level. If you missed your period but your pregnancy test is negative, you may want to test again after a few more days. It is also important to avoid drinking alcohol and drug use long enough to confirm whether or not you are pregnant, as well as any other behaviors that may harm a growing pregnancy.

4. Extreme Dieting or an Eating Disorder

As mentioned before, our bodies are made up of systems. In the same way that stress can disrupt our periods because of how the systems of our bodies work, our periods are also impacted when our bodies lack the nutrients they need. Your period may stop to conserve body fluids, because of an abnormal change in your hormones, or to prevent a pregnancy that could not be supported. 

Research shows that decreased estrogen levels may be to blame for lost periods due to eating disorders (4). Lack of nourishment prevents your body from producing estrogen, which is necessary for your body to ovulate and produce your menstrual cycle. When someone has an eating disorder, their period may occur less regularly or stop all together. 

If this is the cause, it is another way your body is protecting you. Imagine if you got pregnant when you yourself were under-nourished. Your body has the ability to stop ovulating (or ovulates less frequently) to prevent a pregnancy your body would have trouble supporting (5). 

If you think you may have an eating disorder, it is important to reach out for support. Call Eating Disorder Hope’s 24/7 helpline at 1-888-375-7767 today.


Lastly, if you have recently given birth and are now breastfeeding, your period may not return for several months. When you breastfeed, your body needs the hormone prolactin to produce milk. Prolactin, produced by the pituitary gland in the brain, causes your breasts to grow and produce milk during and after pregnancy. 

Prolactin can also prevent your body from ovulating and getting your period. Depending on how frequently and how much you breastfeed, it can take up to a year or two for your period to return after childbirth (6). If you utilize both breastfeeding and bottlefeeding, your period is more likely to come back sooner. If you exclusively formula-feed, your period may begin again shortly after birth.

The hormone prolactin, necessary for the production of breast milk, can prevent ovulation and menstruation.

You and Your Period

Losing your period can mean many more things besides a planned or unplanned pregnancy. Some refer to periods as the “fifth vital sign” because of how much they say about your overall health! So pay attention to your period and how your body is using it to talk to you. If you are concerned about irregular and/or missed periods, contact your medical provider to find out what’s going on with your body. 

At Clearway Clinic, we are a first step for women facing a surprise pregnancy. If you recently missed your period and think you may be pregnant, schedule a free pregnancy confirmation appointment today.

Reviewed by Lynn B., BSN, RN

  1. See https://www.womenshealthnetwork.com/pms-and-menstruation/health-benefits-regular-periods/ for more info.
  2. See https://www.goodrx.com/health-topic/womens-health/how-does-stress-affect-your-period# for more info.
  3. See https://www.yourperiod.ca/normal-periods/birth-control-and-your-period/#:~:text=Periods%20can%20be%20longer%2C%20shorter,first%20few%20months%20of%20use. for more info.
  4. See https://www.medscape.com/viewarticle/747339_2 for more info.
  5. See https://www.eatingdisorderhope.com/information/anorexia/anorexia-amenorrhea for more info.
  6. See https://www.healthdirect.gov.au/breastfeeding-and-periods#:~:text=If%20you%20are%20breastfeeding%20your,year%20before%20your%20period%20returns. For more info.

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