This is one of the most frequently asked questions in my practice. Breast augmentation prior to pregnancy is perfectly safe & while there is a very small chance of trouble with breastfeeding in some women, ultimately it should not affect the ability to breast feed. This is especially true if you opt to have the implants placed beneath the muscle.
That said, if you’re actively trying to get pregnant right now, I’d recommend waiting until after the pregnancy to have your surgery anyway, as it is true pregnancy can often change the shape of the breasts, and even the size. That may then require a possible additional surgery, in the form of a breast lift.