Thank you for your question. Unfortunately, this is not a good idea. Elective operations should be postponed until well after delivery. Additionally, one should wait 3-6 months after finishing breast feeding prior to any breast surgery.
Having breast augmentation during pregnancy would be more challenging that you might think. First, your body is undergoing many changes due to hormonal shifts. Second, you have higher chance of an unpredictable and possibly poor result. Third, and most important, is the risks that are posed to your pregnancy as a result of having anesthesia and the procedure itself, as well as all the drugs that your baby would be exposed to. Realistically, it would be considered malpractice if anyone offered to do the procedure for you. On the other hand, once you have stopped breast feeding for 3 months, you might be a good candidate for the surgery.