I got an email from NSF and my fastlane status now says "approved." However, I've been in close contact with my host PI this last week- evidently, Universities Australia (the Australian partner agency) didn't have funding for me, so my host PI had to promise some funds of her own for my living expenses before they could approve it. You should maybe get in touch with your host PI and see if he/she has been contacted at all. Fingers crossed for you!!!