Hi Sharon, Unfortunately, there is no medication you can take to prevent breast cancer. It does sound like you are doing the right things to monitor yourself (mammogram and ultrasound), though. Talk to your doctor about your fears. If you do go for genetic testing and find that you have the breast cancer gene (which may  or may not based on the case based on your history as you describe it) then your doctor can discuss other options with you. Some women do opt for drastic measures (such as a prophylactic mastectomy) but you are a long way from having to make those kinds of decisions.   Laurie