If the period has been delayed for more than 10 days, the woman has stomach pains, has normal sexual intercourse and is not using contraception, it is important to rule out diseases related to pregnancy, for example, you can use an early pregnancy test to find out if you are pregnant or take a blood test to see if the blood HCG appears elevated. If you are pregnant, you should rule out the possibility of preterm miscarriage or ectopic pregnancy and have an ultrasound to find out the location of the gestational sac. If the test is not pregnancy, it is possible that menstruation will occur, resulting in pelvic congestion, which may cause pain in the lower abdomen, but this pain is not particularly severe, but is often distension, and will improve significantly after rest. If the symptoms of abdominal pain are relatively obvious and gynecological examination reveals pressure pain in the uterine adnexa, it is often caused by pelvic inflammatory disease, and it is recommended to actively give anti-inflammatory treatment and also to give menstrual stimulation treatment.