Husband & sex

I’m 38 weeks pregnant now, and my sex drive is back, yeah you’d think woo hoo right? No. My husband for months now has been upset with me and begging me for sex, and even if I didn’t feel like it sometimes I still would. Well now that my drives back, he doesn’t want to or doesn’t even seem into it? So what am I to think? It’s not a pregnancy thing because it didn’t bother him before. Am I just unattractive now? Is he filling his needs elsewhere or with porn? I just don’t get it, I barely can even arouse him.... and last night I was on top but I didn’t have energy so asked to switch positions and then he just stopped, as if he didn’t want to in first place he just did it because I was doing the work... I’m so upset over this, even though I may be overreacting but I can’t wrap my head around it.. any other time he never turns down the opportunity.