Where can I check when my trial period expire? After 90 days (the lenght of the trial) the created rooms are still accessible. I am planning a session in the next days and I don't want to deal with "I can not enter"-problems.
You should have recieved an email when starting your trial that gives the expriation date. If you can't find that, you should be able to see the expiration date on the Administration landing page. If you are past the expiration date listed, you are at risk of having the account shut off at any point. Adobe may have a grace period after the trial date, but I'm not aware of how long that may last.