Be patient. I can understand it will be nervous, reciept number will be good, to calmeveryone, i see pattern that down grade applications started getting reciepts after straight applications, probably to match to I-140( i m guessing this reason). So reciepts are coming late fot downgrades. I see october 27th folks getting reciepts.. so yours should come soon.
Onething to keep in mind last week on october too many people applied, so for sane date few people reciepts might be delayed too.. hang in there , it will come soon

.. wishing everyone gets reciepts soon..