believe it or not you might be suffering from head hunger and if you feel a constant grumbling in your tummy speak to your surgeon about an acid blocker cause it can be a mask for hunger! Congrats on surgery and I'm sure you will do great!
Yes it is a bit soon for you to be hungry. I agree with Veronica about you possibly needing an acid blocker. Hope your hunger leaves soon as it is a while till stage 3. Also, at least for me, it took a while till I felt comfy digesting food again.