i lvoe the fenway tour and boston beerworks is right across the street and great for lunch. You won't be able to try the beer, but the food is awesome (deep fried pickles- sounds so gross but they are delish and how funny would it be to order those while pregnant?!)
How long will you be in town? If you have a few days, I definitely recommend a drive up to Cape Ann-- Rockport, Gloucester area. You'll definitely find some yummy clam chowder there!
Otherwise, Beacon Hill & Back Bay are lovely to stroll around. Lots of cute shops and cafes. The South End is also wonderful.
If you have more specifics of what you're looking for, I can definitely give you recommendations!