You can track your pages on HubPages using Google Analytics. Sign up for a Google Analytics account and then enter the code they assign you (which starts with UA-) on your HubPages Affiliate Settings for Google Analytics.
Also you can link your subdomain to Google's Webmaster Tools. By this you can gain a better understanding of Google's view of your site and diagnosing problems. Also you can look at your link and query traffic.
For linking your subdomain to Google's Webmaster Tools you should first sign up for a Google Analytics account. Then you can link your subdomain to the Google's Webmaster Tools site by following the below given simple step-by-step guide;
Go to: webmasters tools homepage
Click "Add a site..."
Type in your subdomain
When it asks you to verify your ownership, choose through Google Analytics account...
I must say, linking my subdomain to Google's Webmaster Tools helped a lot in tracking my hubs status and the flow of traffic. I improved my hubs traffic by knowing what keywords were driving more traffic.