You should be able to talk about poo, pee, b.O., boogers, anything in a real honest relationship, no biggie, you're both adults afterall...
This is just fundamental hygiene stuff, you can't get close to someone who stinks, I think he's being passive aggressive if you've asked him politely and he refuses to bathe, but if you've not asked him outright, the fault is your own.
If I were first trimester preggy, i'd wake up, really nauseous, ask if he was going to bathe, then if he said no, smell his arm pit and then vomit right then and there (just kidding). Look if he doesn't care that he makes you physically yark, he just doesn't really care about you...You have a right not to be made ill by anyone including him, stay your distance until he gets the picture!