are you gaining any bodyfat? if not, then you simply aren't eating enough. you'll know that you're in a caloric surplus when you are adding a little fat with your muscle gains. for someone who thinks he is a "hard-gainer" this is probably the best way to gauge that you are actually eating enough.
I have a lot of hard miles on my body from before I realized I'm not 100% invulnerable. Now I just think I'm 75% invulnerable. -Mr. Anthony
Give me a spouse/life-partner who I don't want to punch in the throat when she talks. -Canio6