Like Troy mentioned, you are very concerned, you should hire a professional to really give your house a shake down.
Carpenter ants are big, they can get up to 1/2 inch long, so is you've never seen an ant that big, then chances are that you dont have them.
That doesn't mean that you won't though. They are usually attracted my damp or wet wood, so you should replace any rotting and damp beams in your house and make sure any firewood is in a dry place.
It's always good to get second opinion, I'm telling you what an extermintor told me 2 years ago. Good Luck