Yes, bring the reciept but you need to bring some other proof of citenship. At least that is what the instructions say. When are you interviewing? I'll be there thursday.

Valid U. S. Passport* (copy only picture page)
or Valid Foreign Passport (copy only picture page) and I551 stamp,
or Permanent Residence card
*If you do not have a passport or social security card, you must have one before you come to class. Please place a copy of a receipt showing you have applied for one in the stapled packet for the interview.