No, you need to call your TA and they may be able to tell you. If not then you will find out when the poter takes your luggage from your at the port. He will have a manifest that will tell him what cabin to deliver your luggage to.
CB you will probobly have to fill out luggage tags again . The porter will give you color coded tags. If your tag is grey and says TBA they are useless, you will have to take them off and put on your new ones.
I know someone that called carnival and told them that they wanted to send some friends a gift to their room but did not have the room #. And that they wanted to do it over the internet and the person give them the room #. If they have a room assigned to you they will give it to you.