Google doesn't just start indexing the moment you publish. First you go into a 'sandbox', while Google figures out whether or not you are spam.
When you are still very small (and remember you are competing with sites who receive in a second the kind of traffic you probably receive in a month) Google does not update it's index very often - once every 2 or 3 weeks would be about normal for such a new site.
Add your URL to Google does very little - it's there to make people feel better, but nobody has ever found evidence that Google does anything with the entries at all.
The answer is... be patient. Continue writing good content, work on getting good quality backlinks from relevant sites, and wait for the algorithm to increase its index.