does age play a role in this?

So I'm 20 years old and my partner is 34. In my previous relationships the men I've dated have had a crazy sex drive so the fact that my partners sex drive isn't as high as the men I've come across makes me confused. The oldest I've dated was 31 which was before him and he really enjoyed sex. Now, my partner is 34 and although sex is good, it isn't a daily thing. I'm starting to think that his age plays a big role in it. He's very tired, as he is a general contractor so I can understand. But I also think that even then men are going to be horny no matter what. Some times we go a whole week without having sex and most of the time it's me who initiates it. He rarely does but he's never rejected me unless he's sleepy. Could it be his age or am I not attractive? I mean, he always plays around and touches my ass or boobs. Tells me dirty stuff but even then never complains if we don't have sex or rarely Evers tries to initiate it. I'm also 29 weeks pregnant....