Is it possible to schedule an interview without a conditional approval letter?

Here's a brief timeline:

April 7, 2015: I filled out my Global Entry application and paid the submission fee.

April 10, 2015: I receive the notification that the GOES Account Status changed. I go ahead and schedule my interview (June, 11, 2015).

April 11, 2015: I log back into GOES to try and score a canceled appointment sooner (score! April 21, 2015)

When I go through the instructions on what to bring to the interview, it mentions a Conditional Approval letter.

My home page looks like this (personal details removed)

http://content.screencast.com/users/...04-11_2251.png

I don't see the notification in my message inbox of a conditional approval letter. As I saw in this example:

http://www.thetravelingscholar.com/w...12/12/GOES.jpg



Any suggestions as to what I should do?