Sometimes it takes only 24 hours or even a few hours and other times it takes a whole week.
I'd just wait it out.
Make sure you have a Terms of Service, about us and a privacy policy page as well as a contact us form.
When I first got started with adsense my blog could never get approved even though I had original content, good long articles and much more.
I then later read somewhere that forums got accepted really quick into the adsense program even with little content.
So I started up a forum webmasterbabble.com and it got accepted the next day.
Then I was able to place the ad code on my blog.