My relationship has changed

My husband and I don't normally have a firey love life, just your normal chemistry and deep bonded relationship. Since becoming pregnant, I've noticed a sharp decline in his sexual interest in me. We went from having sex 3 times a week on average to maybe once a week and that one time is almost like a chore. Outside of the bedroom, our relationship is still as solid as ever so that's a positive. I brought it up to him last night and he said it's hard to view me sexually because he's so aware of our baby inside of me and views me as a maternal vessel. I took that pretty hard. I know it's normal for men to be a little hesitant about sex, but just the fact that he no longer has a sexual interest in me makes me feel so depressed. I'm hoping things will get better, but for as of right now, I'm just feeling really blue.