If you have stomach pain, low back pain, and delayed menstruation, you should first rule out the possibility of pregnancy. When someone is pregnant, because the uterus is enlarged, there will be pain in the lower abdomen, especially if the uterus is in a retroflexed position, there will also be back pain, it is recommended that the best way to rule out the possibility of pregnancy is to collect the morning urine and do a morning and early pregnancy test. If it is not pregnancy, clinically it is likely to be due to endocrine disorders, or have had pelvic inflammatory disease, before menstruation, there will be pelvic congestion, so that the original inflammation of congestion aggravated, there will be stomach ache, lumbar pain, it is recommended that gynecological examination, to understand the uterine adnexa whether there is pressure and pain, and clinically give the necessary treatment.