Oral Sex

I can't get my boyfrend to have oral sex on me. Like he looks at my vagina in disgust sometimes which really hurts my feeling, I don't know if it is because im pregnant and my vagina may look, or smell different to him, idk but it really frustrates me because I need to be pleasured, but he finds no interest in it at all. Could it be I tell him about my vaginal problems to much like yeast infections and excess discharge from being pregnant. Idk he seems pretty disgusted when it comes to him having to put his mouth on me down there, how can I change this?