I can find my topics under my profile and in another section, but I can't find them under the specific boards I tried to post (such as under prediagnosis and under leaky gut and other issues.) What am I doing wrong?

Its because they hadn't been reviewed and pinned by a moderator. You should be able to find them now, because they have been pinned.

Since your posts were the same, only one will be kept up. Due to the volume of the board, duplicate postings are not permitted.

Lexie,

Your posts are still there. They have not been pinned by a board moderator yet. Since someone has posted in those areas on a pinned thread, your post actually drops to the last page (or pages . . . I think your leaky gut one was on the 3rd to last page because of all the posts that have been moved). When a moderator reviews it and pins it, it will pop back up to the top. Weekends can take longer to get your topic pinned because the traffic is so much lighter. They check the end pages all the time for topics that didn't get pinned.