The further you are along in your preg the more resilient bubs is to this kind of thing.

I had food poisoning at 18 wks and was petrified, I had food poisoning previously at around 9 wks and had a missed m/c. I had it all checked, bubs was just fine.

Doesn't sound like gastro which lingers for more than a couple of hours - more a bug I think too, especially if you didnt have stomach cramps.