Primary dysmenorrhea does not affect pregnancy. Primary dysmenorrhea is dysmenorrhea that occurs in the absence of other diseases, mainly due to the release of prostaglandins during the shedding of the endometrium, and because of individual differences, some people are relatively sensitive to prostaglandins, which can cause contraction of the smooth muscle of the uterus, leading to dysmenorrhea in the clinical situation, which does not affect pregnancy. In the case of dysmenorrhea you can do hot compresses on the lower abdomen or you can drink hot brown sugar and ginger water, both of which can relieve dysmenorrhea, and it is also recommended that if you are planning to get pregnant and have not been pregnant for six months, you can have an ultrasound examination to find out if the dysmenorrhea is due to other causes.