So you got a receipt from the District Center when you submitted the documents, and then you will have to wait for 60-90 days to get a receipt from the National Benifit Center? (then 90-120 days for I-485?)
The lawyer submitted the documents for me. The short version of my experience is the lawyer didn't do a good job for me, and I don't even know when to get a receipt back from the National Benefit Center!