If you can't receive the receipt,you may find your case INS # from the back of your check that will be
returned by your bank,you may check processing speed
& result on internet;www.uscis.gov/case status &
processing date.
NIW applicants aren't required that must work the same project or same field,as long as he/she still
do a job similar to previous job when he/she filed
the I-140 application.
Don't worry,everything will be OK.