LMP means last menstrual period, which is the specific year and month of the last menstrual period. If a female patient has gynecological discomfort, the first thing we should think about is the time of the last menstrual period, because the time of the last menstrual period is very helpful for the diagnosis and treatment of the patient’s disease. If the patient’s last menstrual period has not come until now, there is a delay, and at the same time there is pain in the lower abdomen or a small amount of vaginal bleeding, in this case we should consider whether it is a good contraceptive measure and whether there is a possibility of pregnancy. Further examination can be done to check the blood HCG or gynecological ultrasound to make a clear diagnosis and then guide the next step of treatment.