Had a similar case 4 months ago. The officer asked me if i had 2 Passport size photo at the end after test and oath. I told him i didnt know i was supposed to bring photo. He said that i didnt read the appointment letter properly. at the end, he made me sign a document and said that the decision cant be made today and will mail me with RFE. He also offered me to get photo and return back within 1 hr. He gave me a document and said that this document will let u enter within 1 hr. I did came back in 30 mins and submitted the photos. i was suspicious that my status didnt change online for 2 weeks. after 2 weeks it changed for oath ceremony and thus i received my citizenship. well gud luck. You should get a letter soon. But the officer should have told you what was the reason why your decision wasnt made. but wait for RFE and go after ward. may be your case was different.