Hi ellee congratulations on your exciting news!!! The covering up is really hard - I tried keeping my pregnancy a secret from my family - but I'm pretty bad at keeping secrets which is why they all know now!!!
Just remember, don't eat
soft serve ice cream(like from maccas)
pate
liver
ready made salads from supermarkets etc
sushi
raw fish
things you don't know how they were prepared (including fruit and veg - you don't know if they were washed or not)

Basically eat things you have prepared yourself or things that have been thorouly (SP?) cooked. Fresh is always best.
Good Luck!