©2018 WebMD, Inc. All rights reserved. eMedicineHealth does not provide medical advice, diagnosis or treatment. See Additional Information.

PMS vs. Pregnancy

  • Medical Author:
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

  • Medical Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

PMS vs Pregnancy Symptoms and Signs Related Articles

PMS vs. Pregnancy Quick Comparison of Differences

  • Symptoms of early pregnancy can be similar to those experienced by women just prior to the menstrual period.
  • At times, it can be confusing to distinguish between early pregnancy and an approaching menstrual period. Women wonder if they may have period symptoms while they are actually pregnant or they may be unsure if they can tell the difference between the cramps of PMS or an early pregnancy.
  • True menstrual bleeding does not occur in pregnancy, although many women experience some light bleeding during the first weeks of pregnancy. In particular, light bleeding around the time of implantation of the fertilized egg is common and occurs at about the time of the expected period.
  • Common symptoms of PMS and early pregnancy include breast swelling, enlargement, pain, discomfort, or tenderness.
  • Early pregnancy symptoms like nausea and vomiting are not common in PMS.
  • The only way to tell if you are pregnant is to take a pregnancy test if your period is late or absent.

What Is Premenstrual Syndrome (PMS)?

Premenstrual syndrome (PMS) is a set of symptoms that occur prior to the menstrual period. Symptoms of PMS begin anytime in the two weeks prior to the onset of menstrual bleeding. Premenstrual dysphoric disorder (PMDD) is a severe form of PMS that occurs in a small number of women. These women have more severe and disabling symptoms.

Which PMS and Early Pregnancy Signs and Symptoms of Are the Same?

Is it just my period or am I pregnant? This is a common question for many women, since certain signs and symptoms of early pregnancy can be similar to those of premenstrual syndrome. Similar signs and symptoms of pregnancy and PMS include:

Which PMS and Early Pregnancy Signs and Symptoms Are Different?

The signs and symptoms of both pregnancy and PMS can be similar and somewhat nonspecific.

  • The bleeding of a menstrual period, however, usually is different from that experienced by some women in early pregnancy.
    • The bleeding of early pregnancy rarely is as heavy or lengthy as with the typical period. Most bleeding in pregnancy will be less heavy (not enough to soak a tampon or pad), and often is lighter in color or brownish.
    • Implantation bleeding usually is light bleeding or spotting that occurs at the time the fertilized egg implants into the uterine wall. This bleeding takes place around the time of the expected menstrual period so it may be confusing for some women to tell the difference between implantation bleeding and menstrual bleeding.
  • The cramping of PMS usually is more severe than cramping women experience early in pregnancy.
  • Nausea and vomiting are more common in early pregnancy than in PMS.
  • Some women with PMS have food cravings (or food aversions); however, they are more common in pregnancy.
  • A white or milky vaginal discharge and darkening of the nipples and/or areolas are signs of early pregnancy that do not occur in premenstrual syndrome.
  • Other signs and symptoms of PMS can include that do not occur in early pregnancy include:
  • For the most part, symptoms of PMS are predictable for a given woman and occur in regular intervals related to the timing of the menstrual cycle.

Can I Have My Period and Be Pregnant?

No, a true menstrual period represents the shedding of the uterine lining in preparation for a new menstrual cycle, and this does not occur in pregnancy. However, as described previously, many women have some degree of bleeding during the early weeks of pregnancy, such as implantation bleeding; that they mistakenly believe is due to a menstrual period. Such bleeding in early pregnancy is typically lighter than that of a true period.

A pregnancy test is the best and only definitive way to tell if you are pregnant.

How Soon Can You Get Symptoms of Pregnancy?

Signs and symptoms of early pregnancy can occur before the missed period and be confused with those of premenstrual syndrome (PMS) or the approaching menstrual period. It is not possible to determine if you are pregnant (in the absence of having a menstrual period) until a pregnancy test is positive.

Health Solutions From Our Sponsors

Reviewed on 1/24/2018
Sources: References

Patient Comments & Reviews

  • PMS vs. Pregnancy - Experience

    Please share your experience with premenstrual syndrome or early pregnancy symptoms, it may help others.

  • PMS vs. Pregnancy - Symptoms and Signs

    What symptoms and signs do/did you have with premenstrual syndrome or early pregnancy?