PMS Vs. Pregnancy Symptoms: Differences And Similarities

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.

PMS Symptoms Vs. Pregnancy Symptoms

Samantha Lynn, a mother from Alaska, explains how distinguishing between PMS and early pregnancy symptoms helped her. She says, “Being familiar with my typical PMS symptoms helped me a lot. If you’re actively trying to conceive and wonder if the symptoms you’re experiencing are related to PMS or early pregnancy, maintaining a symptom journal based on your usual monthly experiences is a valuable strategy. By comparing these entries to your symptoms from previous months, you can identify any unusual changes and consider the possibility of pregnancy (i).”

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).

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.

2. Headaches: Headaches and migraines are common both during pregnancy and before periods.

3. 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).

4. Tender and swollen breasts: You might experience sore breasts, pain, swelling, tenderness, heaviness, sensitivity, and enlargement before your period and in early pregnancy (14).

Lynn shares that 15 days post ovulation, “My breasts were still very sore. That lasted for a really long time. They’re still sore now (at 20 weeks pregnant), but not as bad as they were in the first trimester.”

5. Increased urination: You are likely to experience frequent urination when you are about to have your period and in your early pregnancy (15).

6. Mood changes: Irritability, depression, anxiety, crying spells, and mood swings are all normal before your periods (16) and in pregnancy (16). 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 (17).

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 (18).

3. Shortness of breath: You would have a shortness of breath as the growing uterus pushes up the abdomen, reducing the space for oxygen exchange (19).

4. 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 (20).

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!