Applied on April 27th ? then your status is not on the BMASS yet. BMASS last update was April 20th so if you applied on or after that date, your profile and login has not been created.
Check Embark first, if it's shown complete there, then it will be shown on BMASS later.
The login is as automatically generated once you are in BMASS. Don't have to create one.
If it says invalid username, that means your profile is not in yet.