1.Time: Self-examination can be done on the fifth day after the end of menstruation. 2.Method: Touch the whole breast with the middle and index fingers in a percussive manner and gently touch any lumps or changes under the skin. Look in the mirror and check both breasts for any changes in shape or contour, including nipple overflow, folds, dimples, or changes in the texture of the breast skin. 3. Note: You should not use your fingers to grasp or pinch. 4.Can not completely rely on self-examination, regular examination by a medical professional is more important!