Please check the following :
1. Do you already have a Google Adsense account.
2. If yes, have you configured it in the Affiliate Settings page ?
3. Have you signed up for the HubPages Ad Program ?
If you have done all the above, you should see some earnings atleast by a trickle. If not check Hubpages views and Google Analytics data (if you have configured it). Maybe you are not getting enough traffic to start getting some earnings.
On the other hand, If you don't have a Google Adsense account, please apply for the same and have it included in the HubPages settings. Without an Adsense account you cannot expect earnings from HubPages.