Tender swollen breasts, food cravings, fatigue and slight bleeding and cramping can all be signs of either PMS or pregnancy, according to MedGuidance. However, food aversions, morning sickness and increased urination are all symptoms that occur early in pregnancy, but not with PMS. The only way to confirm pregnancy is by taking an early home pregnancy test or visiting a doctor's office.
PMS and early pregnancy symptoms also both include heightened emotions, constipation and lower back pain, according to MedGuidance. While PMS concludes with menstruation, pregnancy does not. However, some spotting is considered normal in early pregnancy and occurs as the fertilized egg attaches to the uterine lining. Named implantation bleeding, spotting due to pregnancy can be light red to dark brown, and may or may not be accompanied by cramping.
According to MedGuidance, food cravings during PMS are typically associated with sweet and salty foods, while pregnancy food cravings tend to center around odd food combinations. In early pregnancy there may be changes to the color of the areolae, and this does not occur with PMS. If breast tenderness is related to PMS, it fades once the period begins, however, in pregnancy breast tenderness continues throughout pregnancy. Both PMS and pregnancy symptoms are highly variable from woman-to-woman; many women experience some or all of these symptoms, while others experience very few.