First of all I want to thank you for helping all of us under f2a my wife petition and it has been approved my priority date (january-10-2012) I filed my i-485 on August the 2nd my receipt date is August the 5th 2013 I was finger printed on August the 28th on September 12 I received an interview notice for October the 15th at Dallas Texas location my marriage is real obviously, we have every thing under both names since we got married we also have 2 year-old- child together now should I take my child to the interview with me ? then what's my chance to be approved on the spot?? Or they don't approve on the spot because I filed under f2a category??? thanks in advance

Yes, bring all accompanying family member listed in the petition. At the end of interview they will typically tell you immediately (unless they want to do more processing).

My son was born in the US so no need to have him with me?? I've already added my case to the tracker thanks again

Yeah, only bring those people who are listed in petition.