When Minecraft is loaded up, above 'Profile' skin is constantly loading. When you press on 'Profile', the 'Edit Character' and the bin tabs or greyed out and above that there are loading bars where the different skin choices should be. This may not be a problem if you cannot see your skin, however when I try and join anything (a world, server, etc.) it will just say

Loading Skin...

Your selected skin is still loading.