OMG guys - You need to be very very careful when you are answering someones questions... Any inadvertent wrong info could cost someone very dearly.
The WES reference number created is ONLY a reference number, you can use this to track information on WES's website. This is NOT the ECA report number, which is only generated when you actually get the report. That is the ONLY number IRCC cares about... If you mention the WES's tracking number (which in layman's terms is like a FedEx tracking number) then you are landing yourself in trouble.
OK so this is what you need to do - You need to WAIT for the report to come, only then create the profile. I will tell you why
lets say for example I put xyz number as WES, and I get ITA based on that... after you get ITA, in all probability you cannot go back and change the information you entered. Lets say for example that you can - I have seen GCMS reports where they mention what details were changed or corrected post ITA, clear as day.
Lets also assume that you are having a lovely day and IRCC didnt even notice that... and you proceed with the application when you get WES report say 5 days after you get ITA.
IRCC will check that you got ITA on lets assume 1st Jan 2017, then they will see that the WES report was generated on 5th Jan, 2017 ?? Automatically you will be rejected, and probably barred for misinterpretation.
BTW FYI, i tried using random string of numbers and letters back in 2015 for WES when i created by EE profile, within 30 mins my profile was deemed ineligible for this very reason... i couldnt understand why back then, but later i realised it was becoz of this only.
Rest I leave upto you how you want to go about things
Good luck