From your picture it looks like it might has dorsolateral folds? Those are ridges that start just behind each eye and run down the back. Is so, that should make it a Northern Green Frog (they can also spend a winter or two as a tadpole).
Have a look at Frogs and Toads of Virginia The folds are a key feature two distinguish between the species (both have quite variable colouration), and that webpage has a good picture of a Bullfrog and a Northern Green Frog so you can see what the folds look like and know what to look for.