If you happen to be 1st trimester when you go it might not be a pleasant experience if you have morning sickness... I wouldn't like to be rushing to the tiny plane loo every couple of hours for a vomit all the way to Hawaii! Also, in Fiji you would have to be very careful what you eat as preg makes you much more susceptible to food poisoning. In a resort you'd be ok but don't eat anything from a market.