Before Approved:
Opening the thread you will see a notice below the title and above the content saying it is awaiting approval. They may not be viewable by other users or guests.
Not approved:
If a thread has not been approved it gets deleted right away. So you will see them under your profile as deleted, a cross line over the title also you can open that thread and a deleted status will be shown.
If Approved:
The thread will be visible publicly to all members and guests. Further, you can open that thread and check whether its status is one of the above.
Finally, after a few hours or days soft-deleted threads that were not approved and permanently deleted. That means you won't be able to see that thread which was not approved...