[Always *]

you should be safe traveling. It's just the usual stuff you'll be wanting to avoid. Do not drink tap water (bottled only) and i know in some places in South America your also supposed to avoid lettuce because they can't clean it properly (if the water isn't drinkable then why would you want it to be used in washing your food) but I think those recomendations (food wise) depend on the establishment too. So just DO NOT drink the water unless it's bottled.... But that's what your supposed to do no matter what, I'd talk to your regular doctor and see if they think its ok to travel, and it should be fine, it's not as if Mexico doesn't have doctors should worst come to worst, just make sure you've got insurance that'll cover it, and just follow the regular recommendations about what not to eat and stuff like that. Usually your supposed to get Heptatitis shots before going but that might not be possible due to the fact that your pregnant, but just ask. Some locations require you to take other stuff for typhoid fever or what ever, but check the CDC site, it'll tell you what you need or talk to a travel doctor