Is it just me?

Since I became pregnant, I'm super tired...which is normal. But I could care less about sex. My fience thinks I'm just not attracted to him anymore. He is the type that likes it everyday. I used to be the same. But now I could go a week and not care. I still am very attracted to him. My feeling for him haven't changed. But I'm always so tired and could care less about it. I still want sex but on my time...which is not often. Am I the only one? I thought maybe if other women felt the same and commented...he'd understand more.