NC

I submitted my I-485 on last Nov, 06, had couples LUD in early this yrs, then it went silent. :( I am not sure my case has been stuck in NC or something else, after I saw many people got GC and their file dates are even later than mines. feel sad and bad, dont know what are they (Immigration officer) doing? anyone has the similar case? should I make an infopass appointment or just make phone call. based on the uscis processing date frame, they are not supposed to review my case yet, but how come many cases were approved even with later dates, that is what I do not understand.