What has happened is you need to have your posts approved by a staff member before it's shown to the public. The approval process is a system where all posts made by a new user go to the admin, a section that only editors like myself or mods can access. We look over the posts and check that they don't break any rules and that they aren't spam, and approve it if it fulfills these requirements. It is not checked by a computer.
Until a staff member hits the "approve" button, your post won't go up. That means that the time your post goes up is entirely based on when a staff member is online to manage the admin. We're generally pretty good about this, but there are a few occasional gaps in timezones (particularly around Europe), you you may end up waiting a while.
When you can post without having to use the approval system is not based on the amount of time you've spent on the site, but rather by a points system in the site. Once you earn 26 points (which is very very easy), you can bypass the approval system entirely. Details available here.
I've approved your question and your answer. If you have any more questions, please leave a comment.
