Hi k.k.,
Did you use FormsCentral to create the file, or Acrobat? If you used FormsCentral, you'll find your form in your account at Adobe FormsCentral.
If you were using Acrobat, and saved the PDF file, it would've saved to whatever folder you last saved a PDF into. If you choose File > Open Recent File in Acrobat, your PDF form should be listed on the recent files list,
Best,
Sara