Pregnant and confused

Okay so my fiance and I have been together for 3 years and we are currently 7 months pregnant, he works everyday besides weekends and ever since the day I got pregnant we havnt really had much sex, amd we use to have crazy amazing sex all the time before the pregnancy and its getting so hard for me because my hormones are so much and its driving me insane that we never ever have sex anymore, any ideas on why he wouldnt want to have sex? I was thinking maybe cus he feels weird but i found kut when i was 5 weeks pregnant and thats when it all changed so i dont think its because he thinks hes hurting the baby,