Sex???

Just a small rant...my bf works about 80hrs a week, and when he gets home is tired. I totally understand, but what i dont understand is not having any sex! As of right now its been 6 weeks since we last had sex. I am currently 20+4 weeks pregnant. Is it just us or do anyone else go looong periods of time with no sex? Its so frustrating at times. Im not asking for sex everyday, but at least once every other week. Thoughts???