Although I don't doubt that the seeds came out of a Braeburn, I think it is unlikely that what you are growing are Braeburns. Apples do not come true from seed, except rarely when you get a freak seed that thinks it is a cutting. Trees grown from pips are known as "wildlings", and two seeds from the same fruit can produce quite different trees because of the genetic diversity of the material in the seeds. The fruit they produce is frequently not even edible, though you can be lucky.