I assume what you are doing is pulling 3 posts, one or more of which may be ‘Future’ posts, displaying some kind of preview and a link to the complete post. When you click the link for ‘Future’ posts, you get the error.
‘Future’ posts are going to be blocked for people not capable of editing them, more or less the way ‘Drafts’ are blocked. Attempting to access those results in a 404. That is how the system works. Nothing is broken here. Nearly everything can be overridden but why would you schedule a post and then try to display it before its scheduled time?