Why isnt my husband who is 27 making love to me more often?

I am very clean, I dress to impress, try to be thoughtful, romantic, cook, clean, listen, do things together. I buy him suprises yet a lot of this does is not reciprocated. I have tried to communicate about it , it seemed as if he heard me...yet a week later....he is moody & broody, I get upset & end up on the couch while he goes to bed & sleeps like a rock. I am positive he is not cheating. We have only been married 2 1/2 years....so whats the problem?