The absence of menstruation during the cervical cancer vaccination may be caused by nervousness, fatigue, staying up late or poor mood, or endocrine disorder. Generally speaking, there is no obvious relationship between the cervical cancer vaccination and the absence of menstruation. If the absence of menstruation occurs during the cervical cancer vaccination, you can temporarily observe the situation of menstruation next month. If the menstrual flow is low or if you do not have a period for more than 10 days, you should promptly find out the cause. You can have an ultrasound examination to understand the thickness of the endometrium and the condition of the uterus; you can also have a hormone level test to understand the endocrine condition and ovarian function. Based on the results of the examination, treatment to adjust the menstrual cycle should be given.