depends on how fast they are growing. You have only had him a week so give it time. You will notice that their eyes go blue for a day or two. Then they look dull ....then right before they shed they seem to go back to looking normal. Then boom...it happens.
I would boost your humidity up when you notice this. Not sure what you have him in but if it is a viv it is sometimes hard to keep up the humidity.
There are a ton of things you can do. Put in a humid hide, foil the screen top, put a wet towel over the top and spray it down.
Hope this helps.
Ohhhhh also...sometimes when they are in shed...they do not like to be touched. It could be uncomfortable for them. Someone put it to me like this....think of a sunburn. Also when their eyes go blue they cannot see very well. Keep that in mind when handling or feeding.