It takes about 1-2 weeks, sometimes more. They have 30 days to send it.
Be very patient then, and use that time to be prepared for the next steps. Too many people receive their NOA2 after X months and have no idea of what to do next. Being prepared is the key to a successful process.
Also, I don't know how reliable is your lawyer, but do your own research and verify what he/she tells you. Many here hired a lawyer and got an unsmoothed process. The USCIS website and VJ are great sources of information.
Good luck!
Jay-to-the-ling reacted to didopage in JUST FILED my Fiance's 129F oand it was delivered on August 5, 2013!