eventually said:
So, I think it might be OK to still go out of country for 3 weeks and be back by the time I get an appointment ..
Personally I think you should be okay. Here are a few things you should consider:
1. Take a look at the poll started by Pinnacle_man and one started by me last week, both polls conclusively show that there is a high probability of approval within 60 days after FP. So you want to make sure that you have all your documents ready for your wife's derivative application, BEFORE you go home, whereby when you come back you can immediately file for AOS
2. It takes atleast 20-30 days to get an appointment at a US consulate in India, for the spouse, AFTER you get married and show them the paperwork. And it might take some more days to issue a visa.
So all things said and done, move like your ass is on fire. If possible, the day you land, you should get an arranged marriage in a court take the documents file for an appointment. Hopefully you will receive her appointment before you leave for the US, and can bring her back too. If you have your paperwork ready, the day you come back, send in the marriage certificates and you are all set.
Offcourse all of the above is moot if you have already taken it into considersation, and the girl has a green card/citizenship, or is in the same process as yourself.
Regardless, Good luck for both the GC process and the upcoming nuptials.
(*Music in the background* - Another one bites the dust, and another one gone, and another one gone, another one bites the dust!
)