Sex and pregnancy... don't wanna let him down

My biggest challenge right now is not feeling up for sex. My husband and I have a very active sex life but I'm in week 6 and the nausea and gasiness is just making it hard. I'm horny but overcome with the "crappy" feeling overall. My sweet husband hasn't been pressuring me and is totally understanding, but I cant help but worry that this downturn in activity could affect us. I just feel so bad I have to say no when he comes on to me. Anyone else feeling the same?