Well I had a sitemap on my site ( I could swear I did) but noticed the map was not in Google. SO I resubmitted the map. When I checked to see if it was accepted I looked at the details and here is what is said. Sitemap type Web Format Sitemap Submitted 1 hours ago Last downloaded by Google 1 hours ago Status OK Total URLs in Sitemap 379 Indexed URLs in Sitemap 0 Uhhhh why 0 indexed?
I also face this problem in past. but i was wait for that and it was back so as per my experience you just wait.
Don't use the Google Webmaster tool to find how many pages Google had indexed. I was concerned about this as well and had posted a concern in the Google Webmaster Help Forum. I was advised to ignore that count and search for my site on Google instead (site:abc.com) and see the number of results it threw up. The count in my Webmaster Tool was 2, in Google results it was 240+. Also remember that Google doesn't usually index every page on your website even though they are all included in the Sitemap.