The majority of teratomas do not have endocrine functions and will not affect menstrual cycles. If there is a delay in menstruation, the first step is to check for pregnancy. If menstruation is delayed for two weeks, pregnancy should be ruled out, and interventions might be necessary, such as an ultrasound to examine the endometrium or a progesterone withdrawal test. Teratomas do not cause menstrual delays unless a very small number of them have endocrine issues. However, these would not suddenly change the menstrual cycle but would potentially cause long-term endocrine changes from the time the teratoma is discovered.