One in eight women will be diagnosed with breast cancer in her lifetime. Starting in her 20s, every woman should get a clinical breast exam around every three years and, at age 40, begin receiving an annual mammogram, too. These tests are crucial in detecting the earliest stages of breast cancer. However, it’s also important that women get to know their breasts, so they’re able to spot any changes that might be occurring in between exams. Recent health guidelines suggest that formal monthly self-exams aren’t necessary, although you should work to have an understanding of how your breasts normally look and feel, says the American College of Obstetricians and Gynecologists. That way you can point out anything unusual, such as any lump that feels like a pea or a bean, to your doctor.