Forum:Glaceon glitch?

Hello, my name is BlackHeart and I need help,

Here is the story:

This happened in Pokemon Black near the Cold Storage. I was waiting fot a rustling grass to show up so I can take down an Audoino to get some XP for my Vanilite, instead a lvl 23 Glaceon showed up. After that from a normal grass I got 3 lvl 20 Glaceons, 1 lvl 21 and 1 lvl 22 right one after another and this keeps on and on. Is that a glitch, or super rare luck? After I get to the Pokemon Center and come back, I get regular Pokemon again.

I hope you can tell me what is going on, I realy like Glaceon but if it's a glitch, I must leave it because this is against my no glitch/bug/hack aproach.