you won't be able to check whether your application is received through ECAS. Even though the system says you can use your receipt number to check your status, this is not the case. Only file numbers and UCIs are used to check your status, which may be received in the acknowledgement of receipt. If not, it will be on the Sponsorship Approval that is sent out.
At this point, you have quite a while to wait until you receive either one of those. It's been a trend AOR and SAs come within hours or days of eachother. Right now, they are processing applications received on March 21st. If you have tracking information for your package, it's suggested you check that to see if it's been received or signed for. You will not receive any notification that the package arrived.
Also, now knowing it's been less than 2 weeks since they received it, i'm a little more at ease. My gut feeling is that our application has been labeled with a "bring forward date", and they won't even be touching our file again until that 45 day grace period is up... which brings us to the END of may!!! fingers crossed we get the approval before i return in June!!! Regardless, i will be making sure my dear husband calls weekly to check in. 