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Symptoms and Signs of PMS vs. Pregnancy Symptoms and Signs

Doctor's Notes on PMS vs. Pregnancy Symptoms and Signs

PMS (premenstrual syndrome) is a set of symptoms that occur prior to the menstrual period. The symptoms may begin anytime in the two weeks before menstrual bleeding. Pregnancy is the time during which one or more offspring develops inside a woman; from fertilization to birth of offspring, pregnancy lasts about 38 weeks. Similar signs and symptoms of PMS and pregnancy may include weight gain, breast discomfort, headaches, mild abdominal cramping, back pain, fatigue, mood changes and/or emotional symptoms like anxiety, crying, food cravings, and depression. PMS symptoms can wax and wane each month in a non-pregnant woman, but pregnant women may have symptoms all during the pregnancy or some symptoms may last for a month or more and then relent. PMS signs and symptoms of acne and joint pain don't occur in early pregnancy. In pregnancy, a whitish vaginal discharge and darkening of the nipples and/or areolas can occur but does not occur in PMS.

The cause of a normal pregnancy is when one or more fertilized egg reaches the uterus, attaches, and continues to develop; the normal hormonal changes triggered by the pregnancy play a role in pregnancy symptoms. The cause of PMS is due to monthly changes in estrogen, progesterone, and serotonin levels in some women especially during the two weeks prior to menstrual bleeding.

Medical Author:
Medically Reviewed on 6/3/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.