Yes, it is possible you are a carrier from your mother or your dad really is a carrier but didn't show on his test -- how long ago was he tested? How was he tested? There are several quick screens out there that easily could have missed a CF gene mutation. When they started the genetic testing they knew of less than 400 mutations, they are now well over 1000 (maybe something like 1200 or 1300, I'm not sure) but my point is they are identifying new CF gene mutations all the time, it is very possible your father is a carrier. But that is probably beside the point. If you baby is showing sypmtoms of CF she needs to be tested regardless of any known carrier information.
Also you can start with your baby's pediatrician for testing. Be pushy and get what you need. Most doctors want to start with a sweat test. Make sure this is done at an accredited CF clinic because if it turns out to be inconclusive for any reason nobody will want to rely on that information (or they shouldn't rely on it anyway, unless it is an overwhelming positive number) and you will either have bad information or you will just have to go repeat it at a CF clinic. After the sweat test you should INSIST on FULL GENETIC TESTING !!!
Best of luck!