Premenstrual syndrome is a combination of physical, emotional, psychological, and mood disturbances that some women experience after ovulation until their next period. Symptoms last for five to eleven days before the menstrual flow and disappear at the onset of your period (1).
Most PMS symptoms tend to be similar to the early symptoms of pregnancy. This makes it natural to be confused between the two, especially if your periods do not come on time.
Read this MomJunction post to know the unique differences and similarities in the symptoms of PMS and early pregnancy.
PMS Symptoms Vs. Pregnancy Symptoms
Let us first understand the differences between PMS and pregnancy symptoms, and then the symptoms common to both.
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.
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).
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 for some foods and have aversions to some 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 decreases and slowly goes away as the flow ends (9). The cramps and associated pain are likely to 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
- Back pain: You may experience back pain when your period is nearing, and also when you are pregnant.
- Headaches: Headaches and migraines are common both during pregnancy and before periods.
- 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).
- Tender and swollen breasts: You might experience breast soreness, pain, swelling, tenderness, heaviness, sensitivity, and enlargement before period and in early pregnancy (14).
- Increased urination: You are likely to experience frequent urination when you are about to have your period and in your early pregnancy (15).
- Mood changes: Irritability, depression, anxiety, crying spells, and mood swings are all normal before your periods (16) and in pregnancy (2).
These symptoms might make you anxious when you are hoping to have a baby or missed to take a contraceptive during intercourse. You may check for some other unique symptoms that are likely to indicate pregnancy and not PMS.
[Read: Moods Swings During Pregnancy]
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.
- 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).
- 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).
- 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).
- 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).
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.
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 (PCOS), 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).
For a woman without any prior pregnancy experience, the differentiation can be very difficult. So, if you are in doubt, always use a home pregnancy kit. It is important to see a doctor and get all your queries answered.
2. Signs and Symptoms of Pregnancy; UCSB SexInfo
3. Shazia Jehan, et al.;Sleep and Premenstrual Syndrome
4. First Trimester Fatigue; University of Rochester Medical Center
5. Premenstrual syndrome; NIH
6. Natalia C. Orloff and Julia M. Hormes; Pickles and ice cream!Food cravings in pregnancy:hypotheses, preliminary evidence, and directions for future research
7. Marriam Zaka AND Khawaja Tahir Mahmood;Premenstrual Syndrome- A review; Journal of Pharmaceutical Sciences and Research (2012)
8. What are some common signs of pregnancy?; US Department of Health and Human Services
9. Menstruation; Brown University
10. Dysmenorrhea: Painful Periods; American College of Obstetricians and Gynecologists (2015)
11. Aches and pains during pregnancy; U.S. Department of Health and Human Services National Institutes of Health (2012)
12. Signs and symptoms of pregnancy; NHS
13. Sun Min Lim, et al.;The Effect of the Menstrual Cycle on Inflammatory Bowel Disease: A Prospective Study
14. Premenstrual breast changes; The United States National Library of Medicine
15. Genital and Reproductive Health; Princeton University.
16. Menstrually Related Mood Disorders; Center for Women’s Mood Disorders; The University of North Carolina School of Medicine
17. Vaginal discharge in pregnancy; NHS (2018)
18. Cardiac Signs and Symptoms During Pregnancy; Northwestern Medicine
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
- I’m Not Having Pregnancy Symptoms – Is This Normal?
- Early Symptoms Of Pregnancy Before Missed Period
- Back Pain During Pregnancy
- Common Pregnancy Food Cravings