Delayed menstruation and pregnancy differ in clinical manifestations and examinations. 1. Clinical manifestations: (1) Delayed menstruation: it may only manifest as delayed menstruation, mostly not accompanied by uncomfortable symptoms, and may be affected by recent factors such as mental tension, anxiety, and staying up late. (2) Pregnancy: it may also be manifested as delayed menstruation, and due to the elevated hormone levels in the body, early pregnancy reaction symptoms such as nausea, vomiting, fatigue, anorexia, and other symptoms such as breast distension and pain may also occur. 2. Examination contents: (1) Delayed menstruation: ultrasonography can be carried out as prescribed by the doctor to understand the condition of the uterine lining and ovaries, and hormone measurements, such as luteinizing hormone, follicle-stimulating hormone, estrogen, and progesterone can also be carried out. (2) Pregnancy: pregnancy can be determined by blood or urine HCG (human chorionic gonadotropin) levels, and ultrasonography can be performed to determine intrauterine pregnancy as prescribed by the doctor.