My husband and I both had a child when we married in 1999, they are both healthy. My son who is 12 is a cf carrier, we don't know about my 13 year old step-daughter being a carrier or not. Anyways we have a 4 year old CF child together, a boy. We decided to try for another because our plan was to have two children together and we weren't going to let CF stop us. So I got pregnant and had the amino and it came back she does NOT have cf. We did find out recently that she does have a chromosone 9q deleltion, 9q 21.2 q 22.1, so you just never know, we were worried about the CF and then this 1 in 6 million chance thing happened. We love them both, but my point is any of us could walk in front of a car and die tomorrow, you just never know. I say go with it if you want another child and if God decides you get another child with cf that just means he thinks you can handle it and you must be very special parents!
Take care and Good luck!