You can call this number to speak to a representative there: 3046255590
They are very nice and the wait time has been less a minute the three times I called. So please do call and update others by posting to the link Queries referred to. While I was waiting for my background check, it was very helpful to share the information. I sent them an email, but they never replied. It seems like calling it the way to go.
As sd2005 said, they can't tell you the status of your application until after your application is already in the system. When I called today, they were able to locate my file with my name and DOB and told me my background check was processed last Thursday and was mailed out this morning. (They said they received it on Oct 20. I mailed it from CT on Oct 14 with no tracking number, which was a mistake. I should've read this forum before mailing it via regular mail.)
I'd have another set of fingerprints ready to send out in case something goes wrong or your credit card doesn't get charged until the end of next week. It sucks to have to pay for express shipping, tracking, and the $18 fee, but it might be better for the peace of mind.