I turned in my part of the application before I had the recommendation and PFE done. As long as you have typed in the names/emails of the people writing the rec and doing the PFE into the section where it asks, you'll be fine! You can log into your application to check on when your recommendations are submitted, even after you turned it in. The only reason you might want to wait is if you might be changing who is writing your rec. But, with 4 days before the deadline, I would assume that's not going to happen? I would make sure you complete the application in its entirety (including the PFE and rec) before the deadline though. Hope that helps!