Invited for dinner before you've dropped the news?

Camille
Any advice on if to tell people about dietary restrictions when they invite you for dinner? I'm 7 weeks and we haven't told anyone our news yet. We live in France, so when we get invited to our friends' for dinner there's a good chance it could involve unpasteurized cheese, charcuterie, wine, fois gras, etc. I'm also beginning to have a food aversion to beef. :( Don't want to spill our news yet! Any advice or personal experience appreciated.