Menstruation delayed for 26 days menstruation is still not come may be pregnant, but also may be the menopausal transition or menstrual irregularities and other reasons for the cause. 1. Pregnancy: Women of childbearing age who are sexually active and whose periods are delayed for as long as 26 days need to take a self-test or go to the hospital for an early pregnancy test in time, because there is a possibility that the delayed period is caused by pregnancy. 2. Menopausal transition: As ovarian function gradually fails, menstruation will become irregular and may be delayed or advanced as well as increase or decrease in menstrual flow. If a woman is over 40 years old and experiences a 26-day delay in menstruation, she needs to consider whether it is a sign of menopausal transition. 3. Irregular menstruation: After puberty, patients may experience delayed menstruation due to recent stress in life and excessive mental tension leading to menstrual disorders. Delayed menstruation for 26 days may also have other causes, it is recommended to go to the hospital if necessary, for systematic examination, to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment.