It is the weekend in Australia and it has been documented that if applications get kicked into additional processing, they sometimes won't be accepted until a weekday. So you may still be OK, but that means waiting 2-3 days.

If you didn't apply through the official Australian website, but a 3rd party site, then that is not ideal. It could mean additional delays. Please post the link you used to apply so we can help.

If I were you I would obtain my FBI record according to other posts on this thread. If it comes back clean, I would give it until Tuesday AM in Australia to see if it goes through. If nothing happens by then, or if your FBI record comes back with a DWI, then I would contact an immigration lawyer and follow their advice. It sounds like the trip is important to you, and probably worth paying for professional help.