If you don't like the idea of coming inside your pregnant woman, maybe you could go a different way and come on her or in her mouth?

When I was pregnant I was horny as hell and would have happily fucked/sucked my man three times a day, but I didn't have sickness either. I loved him to jack off on me, still love that BTW. Enjoy your beautiful pregnant woman. Know that she has submitted to you in the most profound way possible by opening her body to the new life you've gotten on her. Let her beauty guide you in expressing how you feel about her.