If it was last week and you had listeria you would well and truly be sick by now. (although reading the BB article it seems you can have listeria without symptoms?!) It's so hard eating out when preg isn't it? Sometimes I ask them to microwave something a bit for me just to be sure.

Eta- I had salmonella food poisoning in my first tri and was vomiting every half hour all night and it was less than ideal but all is fine with bub. So you even if you did vomit from the food, it may have been another bug.

Did you see this. https://www.bellybelly.com.au/pregnancy/listeria-pregnancy