They defo don’t sag, you may notice them look a litte more round, like fake looking but it there’s not a lot of natural boob then theres not much to possibly change boob wise! My friend was an A and had 700’s she had to go to a specialist in that extreme sizing. And she had a baby and they went hugeeee!! She lost all her baby wieght and they just looked fake and again. Defo not saggy.
I was an empty empty b and went to a DD and lost nearly a stone and they got a little smaller and that was it. They defo didnt sag!
Good luck! Just be prepared for them to change, but being you was really small you probably wont even notic.
I lost nearly a stone before my second op last week im so bloated and bunged up i feel like ive put loads on again x