When the menstrual period is delayed and accompanied by nausea, it is necessary to rule out the possibility of pregnancy, because in the case of pregnancy, progesterone will persistently increase causing gastrointestinal dysfunction, nausea will occur, and you need to buy an early test paper to test. After the test came out not pregnant, with the body of the endocrine hormones have a certain relationship, because the premenstrual syndrome will cause excessive release of prostaglandins, gastrointestinal tract dysfunction, causing nausea, vomiting, you can be patient and wait for a few days, the general delay of 7-10 days is a normal phenomenon. So as long as it is within this range can be observed, but when it exceeds this range, you need to go to the hospital for ultrasound to determine the endothelial condition, according to the situation can be oral medication to promote menstruation.