It's easier to notice changes if you aren't seeing your turtle every day.
Maybe it's the pic, but look at the first one you posted. To me, the marginal scutes (the scutes on the edge) look like they're curling upward slightly. Is it just the pic, or are the very edges slightly upward? If they are, it sounds like perhaps your hatchling is being fed a bit too much protein.
3-4 regular size reptomin (not the Reptomin Baby, which is a smaller size)? If so, and if the shell is looks like it's curling upward, perhaps feed a bit less (2 - 3 and break them in half) for a bit. He eats the veggies and apple skin?
"You become responsible, forever, for what you have tamed." -Antoine de Saint Exupery-