Hi!
I think you are definitely within the range of normal.
I bf all my children until they were over 2. I was not taking the pill or using any form of hormone based contraception. With my first two, I got AF back when they were 13 months old.
With my third child, AF returned when he was 15 months.
I am hoping with bub #4, that AF stays away until bub is at least 15 months!