Found this on the internet.
Tanning is not good for any part of your body, including your new breasts. Tanned skin is damaged skin. If you want to tan anyway, you are going to have to wait at least until your skin is no longer red and shiny. Tanning too early after your breast augmentation surgery can increase your risk of hyperpigmentation, a condition in which patches of skin become darker than the surrounding skin.
Keep your incisions out of direct sunlight for six months to a year after surgery. Scars take about one year to mature, so cover them! The skin on your breasts will also stretch out and heal before your scars, so if you start tanning, cover your scars with some kind of tape, not just sunblock.