As Mhokdor said, the orcs arrived only several few years ago on Kalimdor. So that would mean that *if* your char was born in the Barrens, he'd most likely be no older than seven years or so. Hence you might want to alter your story a bit. For example, he could've been born in Hillsbrad or any of the other lands in the Eastern Kingdoms where the orcs were either imprisoned in internment camps or in hiding from the humans. Plenty of chance to have your parents get killed by humans there.

Once you've managed to find an alternate story, I'm sure we could review your application again. If you need some help, as said, feel free to contact any orc or sites like Wowwiki.com for example can help you a lot to improve your knowledge on orcish lore. Good luck!
Edit: Locked as Drod already posted a new application.