If you choose to do a breast self-exam (BSE), it's best to do it the week after your period ends, experts say. Some women's breasts get lumpy, tender, or swollen just before or during menstruation, which can make it difficult to do an accurate self-exam. The U.S. Preventive Services Task Force does not recommend BSEs because evidence suggests BSEs do not lower risk for death from breast cancer. The American Cancer Society says BSEs are an option for women 20 and older as a means of familiarizing themselves with their breasts so they can notice changes more easily. Talking with your doctor about the benefits and limitations can help you decide if you should start performing BSEs.