Gastro?

My partner has come down with gastro (diarrhoea & vomiting) i haven't gotten it yet but if i do get it, what do i do? I'm 21 weeks and have never had gastro before (ive worked in child care before my first and always managed to be the only person in the center that never got it) do i let my midwife know asap or?

I apologise in advance if i sound stupid.