They will definitely need to talk about it. If Lois even hints at an abortion, Clark will have to step up and reveal the secret. If there is any chance, and at that point it is better than 50/50 that he is the father then Lois could be aborting a super baby and we can't have that.
They will start talking options in Chapter 11. Clark's secret, however...
I think Clark would want to support whatever Lois' decision would be. After all, he has zero reason to believe that Kryptonian and human DNA can combine in reproduction. He also has zero reason to believe that it won't. Still, adding on the pressure of possibly aborting a super baby isn't something Clark is going to want to do - he would view it as unfair to throw more pressure on her - especially if Lois is undecided on what she might want to do about the pregnancy - factoring in that she may carry to term and then choose to have the child adopted, especially if the baby turns out to be Lex's.
