If you don't have HCV your baby cannot have it regardless of the fathers condition.
Seems like alot of "ifs" here, I mean really IF she gave him Hep-C through sex then IF he gave you Hep-C through sex, then IF you pass it on to your baby..... One would have to guess all that happening would be really low sense the odds are very low that she passed it on to him thru sex to begin with.......... Get tested anyway, myself I would be worried more about the most common things he could have got........ Good luck.
Hep C can be passed along to the baby but is not as common as you think. Even heard of baby being born with it then when tested at 1 yr old virus was gone. Seems as the baby's immune system got stronger it was able to fight off the virus.
Best of luck
Hepatitis C is not generally spread by sex. However, if there was some blood exchange, if the woman was bleeding in the vagina, and your partner had an open cut on his penis or genitals, it is possible. If that happened and he contracted Hepatitis C, then he would have to be bleeding and you would have to have an open cut in order for you to contract Hepatitis C.
While Hepatitis C is difficult to contract through sex, other diseases are more easily spread by sex. These include Hepatitis B, syphilis, Gonorrhea, Chlamydia, HIV, Herpes.
It would be probably be wise for both of you to be tested for these diseases. Then you will not have to worry about whether you are endangering yourself or your baby.
Best of luck.