300cc too big for me?

I am 4’10 and a very petite 78lbs. I am currently a 30aa. I am scheduled for my surgery in 13 days and am super excited but I am second guessing my choice for 300cc. I am getting High profile silicone implants. I want to have them looking natural and not too big, nobody apart from my husband knows I am having the surgery. I am 30 and breastfed all my kids.