My water parameters got funny at the very end, too. Looks like you are waiting on the nitrite converting bacteria (nitrospira?) to mature and get stable. Mine was the opposite. I was waiting on the nitrosomonas bacteria to get stable at converting ammonia to nitrite.
I would hazard a guess that it would be another week for you...my tank ALMOST finished and then had a minor crash and THEN re-established itself. You are doing great and adding Prime is complete peace of mind!! You are going to feel GREAT when it is done, I know I did!!
Something is in the details, but I can't figure out what. It got in while I wasn't looking.