Possible bug with dragons buffs

Ok I went into a custom game and tryed out the new jungle items and then i slayed the 1st dragon which should give u 8% total atk dmg and ability power. So after slaying it I hit C to see my stats and ability power was still at 0. I am not that good at the logistics of these kinds of things so maybe because it says 8% its not an actual increase you should see by reading the stats. But I figured it should be yet my ability power was still at 0 ... this could be a bug so please look into it.