Tarkir pack randomness

So I had a decent amount of packs that I opened and every single pack that I opened the very first five cards were one of each color and in the same rotation, black, green, white, red, blue. They may have started with a different color, but they stayed in that rotation. Has anyone else noticed this was this on purpose or are all sets like this? The SPG drop was always the 7th/8th card.

Or am I just undiagnosed autistic?

This is my first release since I got into Magic.