(((((((((((((( LMo & Dad ))))))))))))))
I too lost my mom to brain cancer, stage 4. She did go through surgery and radiation treatments only to find that it grew like crazy. But I can say that the surgery and all gave her a few more months of life. She was in no pain, so that was good.
Right now hon, you are starting your grieving process. You are preparing yourself for the inevitable. It's not easy of course. Lots of different feelings. What I can say though is this....if you go hug him, hold his hand, talk to him, do whatever you can do to have a touch of intimacy with your dad now....it will be a wonderful thing for the both of you. Mom and I weren't that way through our lives either, but I did reach out to her and even if it seemed she didn't respond in kind all the time, I ended up with memories of how I cared for and loved my mom, regardless of our past history. And those memories mean all the world to me and I'll bet they will to you too.
As for your fathers seemingly indifferent feelings regarding your pregnancy.....it's not as if he isn't happy for you. Possibly it's because the disease is affecting his brain, hence his emotions and thought patterns are different and not functioning properly.
I'm so very sorry about all this LMo

You and your family are in my prayers.
*Gentle Hugs*
sabby