How exciting for you! I was in Japan in 2004, I had just found out I was pregnant in Rome the week before so I was about 4 or 5 weeks by the time I got to Japan.

I didnt have a problem with food at all, including sushi as it was incredibly fresh. We had Japanese friends there though & they were the ones who made the sushi so I know it was fresh & safe. They all told me to eat it as it was "healthy for pregnant woman". If you think about it, Japanese woman eat sushi etc throughout their pregnancies & they have healthy babies.

I found it very hot (we were there in August) so I always had a bottle of water with me.

As for the English barrier, most of the Japanese can speak broken english & will go out of their way to help you. I'm sure you wont come into any health problems but if by the off chance you do I'm sure you'll be fine. Try not to stress & enjoy your holiday

On the flight I did small walks now & then but didnt have any probs.

I hope you have a great holiday, I'm sure you'll love it over there.