8 months pregnant with menstrual like cramping in lower back every 3-5 minutes.. very painful and uncomfortable. ?

Labor contractions?: Pregnant women who get regular cramps in the lower abdomen may be having contractions that need to be stopped, unless it is close enough to full-term that the baby can come out (usually 37 weeks or later). So, if cramps come frequently, one must call her doctor and/or go to the Labor and Delivery ward at the hospital to get checked out. This scenario can happen more than once in a pregnancy.