PMS Vs. Pregnancy Symptoms: Differences And Similarities

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Most women may have heard about premenstrual syndrome (PMS) but wonder about its difference from pregnancy symptoms, leading to the PMS symptoms vs. pregnancy symptoms curiosity.

Premenstrual syndrome (PMS) may present as a group of symptoms affecting your physical, psychological, emotional, and mood status experienced by some women during the period between ovulation and the start of menstrual flow.

The symptoms of PMS vs. pregnancy may be difficult to distinguish and may cause you to be confused. However, PMS symptoms last for about five to eleven days and usually disappear at the onset of your period (1). Read this post to learn more about the distinct differences and similarities in PMS and early pregnancy symptoms.

In This Article

PMS Symptoms Vs. Pregnancy Symptoms

Let us first understand the differences between PMS and pregnancy symptoms, and then the symptoms common to both.

1. Bleeding

PMS: You may not have any bleeding or spotting until your period starts. Once the period starts, you might have heavier bleeding that could last for a week.

Pregnancy: You might see light spotting (pink or dark brown) at the time of implantation (happens 6 to 12 days after conception) when the embryo attaches itself to the uterus (2). It may last for a couple of days and is shorter than a menstrual period.

According to Dr. Kirti Patel, a board-certified gynecologist from Greater Boston, Massachusetts, “Most people do not notice implantation, however some report cramping, a light bleeding, or spotting. Thereafter, if implantation does occur, hormone levels will increase and symptoms of pregnancy can start to develop. When in doubt about whether you’re having PMS symptoms or early pregnancy symptoms, I suggest a pregnancy test.”

2. Fatigue

PMS: You may feel exhausted even if you have not done anything strenuous, and it goes away when your periods are round the corner (3).You may deal with your fatigue by practicing some exercises that could improve your sleep.

Pregnancy: If your periods are delayed, and you are experiencing extreme fatigue, it can be a symptom of pregnancy. It may last throughout the pregnancy due to the surge in progesterone levels that causes a drop in blood pressure and sugar levels. Good nutrition, deep breathing exercises, short naps, and drinking enough water during the day might help (4).

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Joint and muscle pain is also a common symptom of PMS, which may or may not be present in early pregnancy (24).

3. Food cravings/aversions

PMS: Your eating habits are likely to change when you have PMS. You may crave sweets, chocolates, carbohydrates, or salty foods, and you will develop a ravenous appetite. Although you crave for some food (5), you can easily resist the cravings and temptations.

Pregnancy: You may have extreme cravings an increased appetite for some foods, and aversions for others. Some women also suffer from a food eating condition – pica – where they feel like eating non-food items such as dried paint flakes, metal pieces, and ice. In this case, you should consult your doctor immediately (6). These signs do not show in a PMS.

4. Nausea and vomiting:

PMS: Women do not nauseate or vomit when their periods are late, but in rare cases, you may experience nausea (7).

Pregnancy: Most women feel nauseous during early pregnancy. If your periods are delayed, and you are extremely nauseous, you may be pregnant. Nausea begins any time after two to eight weeks post-conception and continues throughout pregnancy. It is known as ‘morning sickness’ that may occur at any time of the day (8).

5. Abdominal or pelvic cramping:

PMS: Cramps or dysmenorrhea during PMS is common, and the severity varies according to genetic disposition and body system. However, as bleeding starts, the pain and bloating decrease and slowly disappear as the flow ends (9). The abdominal cramps and associated pain will likely reduce with age (10).

Pregnancy: When the fertilized egg embeds into the uterine wall, it may cause mild abdominal cramping along with spotting during early pregnancy. You may experience cramps in the lower back or lower stomach, which continues for weeks or even months, lasting much longer than PMS cramps (11).

Similarities Between PMS And Pregnancy

If you have the signs listed next, it may be difficult to say whether it is an upcoming period, or you are pregnant (5) (12).

  1. Back pain: You may experience back pain when your period is nearing, and also when you are pregnant.
  1. Headaches: Headaches and migraines are common both during pregnancy and before periods.
  1. Constipation: The progesterone hormone leads to digestive issues such as constipation. As these levels rise during the second half of the menstrual cycle, it affects women experiencing PMS too. Also, hormonal changes early in pregnancy could cause constipation (13).
  1. Tender and swollen breasts: You might experience sore breasts, pain, swelling, tenderness, heaviness, sensitivity, and enlargement before your period and in early pregnancy (14).
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Premenstrual breast tenderness is usually intense just before periods. However, breast tenderness during pregnancy may persist throughout the first trimester (14) (25).
  1. Increased urination: You are likely to experience frequent urination when you are about to have your period and in your early pregnancy (15).
  1. Mood changes: Irritability, depression, anxiety, crying spells, and mood swings are all normal before your periods (16) and in pregnancy (2). According to a study published in the Journal of Psychiatric Research, it was found that mood remained generally stable throughout the study period. However, there was an initial decrease in positivity and an increase in irritation across all samples and subsamples during the first trimester. Among participants in the long-term observation group, positivity increased and irritability decreased during middle pregnancy, but slightly reversed again in late pregnancy.

These symptoms might make you anxious when you are hoping to have a baby or miss taking a contraceptive during intercourse. You may check for some other unique symptoms that are likely to indicate pregnancy and not PMS.

Dr. Patel says, “PMS and pregnancy can both cause similar symptoms due to very different reasons. In the case of PMS, the symptoms are likely due to a peak in hormones that occurs during the week before the period begins. Estrogen peaks in the middle of the cycle around the time of ovulation, and progesterone peaks right before the period begins. In the case of pregnancy, there is also a rising level of estrogen and progesterone, but there is another hormone called the human chorionic gonadotropin that peaks in the first trimester.”

Unique Pregnancy Symptoms Less Likely To Occur During PMS

Some symptoms are specific to pregnancy and might not show in case of a nearing period or PMS.

  1. Darkening of the nipple: Estrogen levels in the body increase, leading to the expansion of the areola size or nipple. As the pregnancy progresses, this development leads to the darkening of the areola, which may remain dark, even after delivery (2).
  1. Changes in cervical mucus: One of the common indications of ovulation is changes in the cervical mucus. If a woman has conceived, then the mucus becomes white, milky, and is thin. It could be sticky, as well (17).
  1. Shortness of breath: You would have a shortness of breath as the growing uterus pushes up the abdomen, reducing the space for oxygen exchange (18).
  1. Increase in basal body temperature: If you are pregnant, the basal body temperature (BBT) increases slightly between 0.5 and 1.5°F shortly after ovulation and continues to be high during pregnancy (19).

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Many women experience a metallic taste in their mouth during early pregnancy, which may occur randomly throughout the day or when a certain food is eaten (26).

It is essential to know the right reason behind your symptoms, as that would help determine whether or not you are pregnant. The best way to find the difference between PMS and pregnancy symptoms is to take a home pregnancy test in case your period is delayed.

When Should You See A Doctor?

It is good to consult your doctor for any unusual symptoms or any concerns you may have with the symptoms.

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It is best to take the home pregnancy test a week after you’ve missed your period (26).

If you noticed a positive result with a home pregnancy test, then your doctor may confirm it with further testing. If further testing yields a negative result for pregnancy, but your periods do not resume, then the doctor might perform further testing. Medications will be prescribed based on the underlying cause of the condition.

In the next section, we answer a few common questions related to PMS and pregnancy symptoms that you may have at the top of your mind. Read on!

Frequently Asked Questions

1. What is the menstrual cycle?

It is a monthly series of bodily changes a woman experiences to prepare for pregnancy. One of the ovaries releases an egg every month (a process called ovulation), and the hormones keep your body healthy to prepare the uterus for pregnancy. If ovulation occurs and the egg is not fertilized, the uterine lining sheds away in the form of the menstrual period. A menstrual cycle is counted from day one of the period to the first day of the successive period. An average cycle lasts 28 days, and cycles range from 21 to 35 days in adults to even 21 to 45 days in teenagers (20).

2. When does PMS start?

PMS symptoms usually start around day 14 of the menstrual cycle and may last until one to two days after your periods commence (21).

3. Is premenstrual syndrome normal?

Premenstrual syndrome is normal. Only a few symptoms disrupt daily routine by bringing in a wide range of physical, emotional, and behavioral changes. Making a few simple changes and adjustments in routine can help you get through PMS. However, in the case of PMDD, you must see a doctor.

4. Do women with PMS see hormonal changes?

From PMS to menopause, the changing hormones are likely to affect weight and mood. They also affect the brain’s serotonin, showing considerable changes in mood, often resulting in mood swings. In some women, PMS may be smooth without any adverse changes or effects, while in others, it may be a shipwreck at every hormonal fluctuation (22).

5. Can you have PMS while on birth control pills?

Some women say that birth control pills reduce PMS symptoms, while others experience severe PMS symptoms. The hormonal changes and drop in hormonal levels during PMS will not occur if you are on birth control pills. This means there would either be less or no PMS in some women. In some instances, however, the hormones will fluctuate while on birth control pills and manifest into PMS (23).

6. Can I have PMS but no period?

You may have PMS but no periods for several reasons. They could be polycystic ovary syndrome (PCOSiXCondition where ovaries release more levels of androgen (male sex hormones) causing cysts in ovaries and altering the menstrual cycle ), anemia, psychological stress, nutritional imbalance, contraception, weight loss, strenuous exercise, and more.

7. Should I get treatment for PMS?

Treatment might help you manage PMS so that it does not affect your daily activities. Diet and lifestyle changes could help in the case of mild to moderate PMS. But if it is severe, your doctor will prescribe medication or suggest treatment methods. The success of medical treatment, however, varies from woman to woman.

8. What dietary and lifestyle changes can I try for relief from PMS?

You may take nutritional food, including vitamins, exercise, de-stress, and consider herbal remedies for relief from PMS.

9. What about herbal remedies for PMS?

Evening primrose oil, chaste tree extracts, saffron, Ginkgo Biloba, and St. John’s wort are some herbal remedies that might relieve PMS symptoms. However, you should check with your doctor before including them as they can cause side effects and drug interactions (23).

10. Can you still get PMS symptoms if you are pregnant?

You cannot have PMS symptoms when you are pregnant, as you are not premenstrual. Pregnancy has its own set of hormonal changes and symptoms.

11. How common is PMS?

About three in four menstruating women experience some form of PMS symptoms in a lifetime. Some may experience mild symptoms, while less than five percent of women in their childbearing age are likely to have PMDD (premenstrual dysphoric disorder), a severe form of PMS (1).

12. At what age does PMS go away?

You may stop experiencing PMS only after menopause when you no longer get a period (27).

13. Can you have zero pregnancy symptoms before a missed period?

Yes, some women may not experience any symptoms of pregnancy for a few weeks, which usually coincides with the time when the next period is expected (28).

Knowing the difference between PMS symptoms vs. pregnancy symptoms can help you avoid unnecessary expectations and concerns. Vaginal bleeding, fatigue, food aversions and cravings, abdominal and pelvic cramping, nausea, and vomiting can be seen in premenstrual and early pregnancy. Symptoms such as mood changes, increased urination, breast tenderness, and constipation can also be felt. Changes in cervical mucus and darkening of the nipples are unique pregnancy changes. You may wait for the expected menstrual date and check home urine pregnancy tests if menstruation does not occur, and seek medical care for further guidance.

Infographic: Can Other Conditions Mimic PMS?

Various physical and mental health disorders and conditions can mimic PMS. Usually, these conditions can cause symptoms throughout the month, while PMS may only have the symptoms around menstruation. Go through the infographic to know various disorders that mimic PMS and its hallmark symptoms.

differential diagnosis of pms (infographic)

Illustration: Momjunction Design Team

Get high-quality PDF version by clicking below.

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Key Pointers

  • Premenstrual symptoms can affect a woman’s emotional, physical, and psychological wellness, and typically last between 5-11 days before the start of the menstrual period.
  • Bleeding, cramps, abdominal pain, and fatigue are common symptoms that vary in frequency and intensity with PMS and pregnancy.
  • Back pain, headache, constipation, tender breasts, mood swings, and frequent urination are some common symptoms of both pregnancy and PMS.
  • Unique pregnancy symptoms include elevated basal body temperature, darkening of the nipple, and changes in the consistency of cervical mucus.
  • It is ideal to consult a doctor when experiencing any unusual symptoms during the menstrual cycle or pregnancy.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
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19. Kaitlyn Steward and Avais Raja; Physiology, Ovulation, Basal Body Temperature; StatPearls Publishing (2020)
20. Menstrual Cycle; US Department of Health and Human Services
21. Premenstrual syndrome; The United States National Library of Medicine
22. Reproductive health and mental health; US Department of Health and Human Services
23. Premenstrual syndrome: Treatment for PMS; Institute for Quality and Efficiency in Health Care (IQWiG); Cologne, Germany
24. What is PMS (Premenstrual Syndrome)?; Planned Parenthood Federation of America Inc.
25. Breast Pain: 10 Reasons Your Breasts May Hurt; Johns Hopkins Medicine
26. Am I Pregnant?; Cleveland Clinic.
27. Premenstrual syndrome (PMS); Us Department of Health and Human Services
28. Symptoms of early pregnancy; American Pregnancy Association
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