I agree with the 'take it slow'ers! Small changes are good changes!
Don't stress about low fat yoghurt- go with normal full fat yoghurt with cultures- it'll help you stay fuller for longer and give you a good protein hit at the same time!
Go BROWN! Brown bread, brown pasta, brown rice- all have better nutrients for you and your bub and will help you stay fuller....for longer!
Veggies as snacks are my life at the moment
Capsicum- especially red is a great healthy snack you can eat whilst boosting your metabolism (ever so slighty LOL)
I haven't gone off chocolate all together- I've switched to dark- means I don't eat so much of it because I don't like it AS much, but I still get a choccy hit

And I know it's easier said than done, but don't stress, you're growing a bubs and you'll be needing the energy to take care of one too- it's a long journey puytting the weight on, and it'll take just as long to take it off- but...you can do it!

hahaha... wrote that last part as a reminder to myself as well! LOL