It’s important to let your body heal after your original augmentation procedure to allow all post-operative swelling to disappear. At that time, you should see the final results of your breast augmentation. For these reasons, you should wait at least six months after your initial augmentation before considering revision for cosmetic reasons.
There may be medical reasons for intervening before six months, such as pain or discomfort or complications from infection. These kinds of problems, of course, require immediate attention.