Sometimes, when you submit a post, it may seem to disappear.
This may happen when you submit a post with a link in it. When this happens:
Your post hasn't disappeared; it has simply been moderated. The board software has detected a link, but the board software isn't intelligent enough to know if it's spam.
So the board software hides it from public view, but moderators can still read it. When the moderator has looked at the post and decides that it is not spam, he or she can "approve" the post, and then it will be visible to everybody.
Please don't try to resubmit your post. All that happens is that all your posts get moderated and queue up for approval. Just wait for a moderator to approve your post.