Adjustment of Status - I-485

Hi my name is Alamgir Hossain , I came to the US with student visa, and I got married January 2015 and had our interview today at 26 federal plaza , New York.

We went there about an hour before our interview, so we got called like after 45 minutes after of our check in, IO was kind of rude because both of us don't speak English properly so we requested interpreter,
She asked my wife three four question like what is your name? how old are you? When you meet your spouse for the first time? What is your current address? thats it. Than she asked me the same when I meet her for the first time, How old I am, what is my address, how long we have been living there, how I came to the US and when, and she also asked me how long I have been living here in the US?
Than she started asking If I have any document that I want to submit, we gave her a lot of documents, like our bank statement, insurance,our car title, mobile bill, internet bill,electric,like all utilities,joint tax return, and we had four big albums of our pictures, when she saw them she said I don't need anymore stuff and she asked if we want we can give her one or two pictures of us, than I gave her three of them she took only one and said I don't need more, than she went through all of the documents we gave it to her and she was look like fully satisfied, than she print out a paper and told me she gonna review everything looks fine, if there is no problem I will receive my green card within 6-8 weeks, than she asked me if I have any more questions, I said no, than she said you guys have a good day and showed how to go out of the hall. I am so much worried is it normal for New York, the interview was about 15-20 minutes long, we answer all the question smoothly and we had no issues with the documents and anything else, Can anyone Please help me ? I dont know should I be really worried or it is normal for New York I will really appreciate You guys help.