There is no total number of posts for a week or day. There is just a wait time between posts, sort of like a cool down time to stimulate users to read more then they post.
I never had the problem of not being able to post because I had to wait, even when I was a newbie. It probably happens quite a lot to newbie shitposters, although in this case I have looked at the OP's post history and he doesn't seem to be. I guess it would be a coincidence of writing two posts very fast and he got the message about having to wait.