Do u think I will need retainers? please answer only if I have experience..?

I just got my braces 1week.ago, and my dentist says I won't need retainers after the braces come off, I am using innovation c, ceramic self ligating braces.. He says after 6months my teeth will look good and after 6more months or so my braces will be removed, do u think I wil need retainers?