While we were ttc, we were referred for tests as things just weren't happening for us (2 years ttc). We found out to our amazement that DH is a CF carrier.
No-one in his family has CF or has said that they are a carrier. We have told DH's parents so that they can get tested if they want as one (or possibly both) of them must be a carrier too. Obviously there are implications for DH's cousins. As far as I know, DH's parents have not been tested. I think they're finding it a bit hard to get their heads round as there is no family history at all, they may not realise what this might mean to other branches of the family.
We had genetic counselling when we found out, but it took about 8 weeks for us to get the appointment. We had no idea what the implications were for our ttc or any future children. I was also tested, but I am not a carrier. This means that our dd could be a carrier, but could not have CF. We have been told that we should have dd tested when she is about 14-16 and old enough to understand the implications, but before there is any chance she might want a baby. Obviously if she is a carrier, then future partners with whom she wants to have children will need to be tested. Apparently 1 in 25 people is a CF carrier. Our GP told us that as it is so common, there is now research being done into the implications of including it in post-natal or pre-natal screening.
We have also found out that the type of gene mutation DH carries can cause infertility in men.
Not sure if this is the sort of info you need, but hope it helps.