My rune page isnt displaying what I actually have, plz help

Hi, Ive been noticing that I dont start out with very much ap when I start a game. My ap rune page consists of 23 flat ap, 9 armor, and 7.83 mag pen. However, when i load lolnexus it keeps on telling me that i have 9 armor, 7.83 mag pen and 14.85 AP. I dont know why it is doing that but I am really confused. I would appreciate it if someone could help me with my dilemma here. Thanks