There are several different reasons for not having a period for 1 week: 1st, it may be a normal physiological symptom, women may have problems such as early or late menstruation, usually 3-7 days early or late is normal, there is no need for treatment; 2nd, consider the occurrence of menstrual disorders, if this situation often occurs, consider that it is due to endocrine disorders, mental tension or environmental changes and other problems. If you have had unprotected sex before menstruation, the delayed menstruation may be a symptom of pregnancy, so you need to go to the hospital for examination to determine whether there is pregnancy.