Endometrial thickness of 13mm means I am ready for menstruation.

It is not certain whether the endometrial thickness of 13 mm is ready for menstruation. It needs to be analyzed based on the examination time and other results, as follows:

Before menstruation, the thickness of the endometrium can usually reach 10~15 mm. If the examination time is according to your usual menstrual cycle, when your menstruation should come, then if the thickness reaches 13 mm, it usually means that your menstruation is about to come. You can continue to observe to see if your menstruation can come on time.

The endometrium will continue to thicken after pregnancy. Therefore, if menstruation is delayed and the thickness of the endometrium reaches 13 mm, it is possible that you are pregnant instead of menstruating. You need to go to the hospital to test whether you are pregnant.

If endometrial lesions occur, such as simple endometrial hyperplasia and endometrial polyps, the endometrium may thicken to 13 mm, but it does not necessarily mean menstruation will occur. It is necessary to take an endometrial biopsy and test sex hormones for analysis. According to the examination results, follow the doctor's advice for treatment.