Not getting the Free Champs for the week

I recently hit lvl 10 but I still have the same champs I came into the game with. This being Caitlyn, Nocturne, Miss Fortune, Sona, Nami etc. Everywhere I look, it says that you have to be lvl 6 to receive the champ rotation for the week. I just want to confirm if that's right, or if there's another lvl I have to hit to be able to use the free champ rotation that comes every week.