New posts not appearing on homepage

My blog launches next Wednesday, and for whatever reason when I do tests posts, they don’t show up in reverse order on the homepage – they did before, but now for some reason they do not. I already went to the reading settings, and that’s all fine – not a static page, set to show my latest posts. I am using some basic plug-ins, including a few from my theme (X).

Any suggestions? I’ve got 9 days to fix it!