My posts get indexed almost as soon as I hit publish. After I publish, I sometimes do a site operator search for the new post's title and it is there in Google within 10-20 seconds.
Instant indexing could be because you have a very good ping list or because you have the google bot on your site at that moment. If you have a lot of fresh backlinks pointing to your site, Googlebot is probably always there...
P.S - Why would this affect your posting. Post as much as you can, always. It can only be good for you.