Don't is right, which is only to be expected.
If you are ever in doubt as to how your iPad is accessing the internet it's pretty easy to tell, once you know what you are looking at.
If the iPad is on WiFi, it says iPad in the left corner and shows a fan shaped signal strength indicator. If it's on 3G it will display your carrier's name, say 3G, and show signal strength by a series of bars. On AT&T it might show an E (or E something, can't remember at the moment) which means you are on their slower Edge network. If it has neither of these, but shows signal strength you have an even older and slower connection. Short of getting text messages it's all but useless that way.
One more, if it's connected to your iPhone's hotspot via bluetooth it says iPad and you get a little two link chain icon. I noticed that when I was experimenting the other day.