The 40s do not have menstruation on time may be pregnancy, menopause, endocrine disorders, mental tension and so on. 1. pregnancy: women’s menstruation is the egg into the uterine cavity without fertilization of the corpus luteum failure, estrogen and progesterone plummet endometrial necrosis and shedding of the formation of a woman pregnant after the fertilized egg will grow in the uterus, menstrual corpus luteum change into pregnancy corpus luteum, so it will not come to menstruation. 2. Menopause: women in their 40s are considered to have entered menopause, when the function of the ovaries declines, the body’s hormone levels will fluctuate, there may be menstrual abnormalities. 3. Endocrine disorders: Obesity, excessive dieting or irregular living can cause endocrine disorders in women, and hormone levels in the body will also change, resulting in delayed menstruation. 4. Mental stress: If women in their 40s usually work under pressure, mental stress will affect the function of the hypothalamus, delayed menstruation. There may be other reasons why you don’t have your period on time in your 40s, so it is recommended that you go to the hospital in time to improve your examination and clarify the cause of the problem, and then give targeted treatment or therapy under the guidance of your doctor.