Even though some can go for a very long time without eating, if you've had one for two years and you start to get worried about not eating that's a sign something might be going on. I only have the one pac, but with my other herps it seems like you know right off which ones are prone to 'fasting' and which ones won't refuse a meal unless they're sick.

Like Grif said, post a picture of the frog and the setup info. Is he acting normal otherwise? As in, is he burrowing more/less than normal, soaking about the same amount, ect. ?