Hi Megan,
Oh you poor love! I hope you're feeling better soon hun, but try not to worry too much. Like Bec said gastro is not dangerous to bubs, but try to keep up with the fluids. It's so easy to pick up stuff like this ! A few of my preggie friends have had gastro and you just have to wait for it to pass unfortunately. It's good that you've rung the midwife as now you know what to do it if the bug keeps going (which I hope it doesn't!).
Please don't stress hun, I know it's so easy to do in our cases, but be assured it's just a bug and it will pass soon
Big hugs
B xxx