Delayed menstruation nausea is not necessarily a symptom of pregnancy, if the blood or urine test did not find pregnancy, basically can be ruled out. It may be due to irregular menstruation, mental overstress leading to the emergence of premenstrual syndrome, often manifested as nausea and vomiting, irritability, abdominal pain, breast distension and other manifestations; in addition to menstruation, the body’s hormonal changes, resulting in gastrointestinal disorders, peristalsis weakened, gastric emptying time is prolonged, the accumulation of food is easy to nausea; in addition to menstruation before the eating of unhygienic, stimulating food, can also be nausea symptoms. In addition, eating unhygienic and irritating food before menstruation can also cause nausea.