Whether a woman’s endometrial thickness of 3mm is normal or not depends on the patient’s specific situation. Because the thickness of a woman’s endometrium is affected by many factors, such as different times of the menstrual cycle, the level of estrogen and progesterone, luteinizing hormone, follicle stimulating hormone and other such hormones, it can be affected by the patient’s age and the function of the ovaries, so the thickness of the patient’s endometrium varies. If the patient’s endometrial thickness is 3 mm, it is just after the end of menstruation or after the patient is menopausal, in this case the patient’s endometrial thickness is normal. If the patient’s endometrial thickness of 3mm is during ovulation or before menstruation, the patient’s endometrial thickness is abnormal and thin. This is because normally the endometrial thickness should reach about 0.7-0.8cm during ovulation and about 1.0cm before menstruation.