The normal menstrual cycle lasts from 21 to 35 days, with an average of 28 days. Having a period once every two months indicates the presence of endocrine hormone imbalance, including environmental, stress and mental factors that may cause a month delay in menstruation. In this case, you can first observe that there is currently only one, once in two months, and observe whether there is such a situation in the next month, if the next month has returned to the normal menstrual cycle, it will not affect the health. If it occurs frequently, you should take a blood test for endocrine hormone 6 on an empty stomach on the 2nd-5th day of your period to rule out any endocrine hormone disorders. Depending on the situation, you can also consider taking oral cycle regulating drugs to regulate your menstruation, such as Glaxo plus progesterone, short-acting contraceptive drugs, such as Eusyn, Eusyn or Daing-35, for 3 months after discontinuation, and then stop the drug to observe the effect of regulation.