Yes, it does. Just not quite yet.
Evil creature (HD)---10 or lower---11 to 25---26 to 50---51 or higher
At 7 HD, you won't blip on a Detect Evil spell. You will once you hit 10 HD however, though your Evil Aura will be a faint one.
If you're found out, you're in trouble. Metagame speaking, is...