Not telling certain family members

Amy • Mom to 4 beautiful girls. 3/3/10, 4/27/14, 4/8/17, 3/7/19.
So a few people have told me I'm in the wrong, so I kinda like different opinions, but overall I'll most likely stick with my choice. My father has never really been involved in my life whatsoever and the little that he has been hasn't always been that wonderful. We used to talk pretty regularly though, but when I got married 2012 he completely stopped calling me. If I wanted to talk to him I had to call and put in all the effort. This past year I've tried to be respectful and call on holidays, birthday, etc. but I'm just over it and he never answers anyway. Told me he was divorcing my stepmom via text, told me he was kicking me off his insurance via email. Never texts to say thanks for the phone calls never calls on his granddaughters birthdays, etc. I currently 18 weeks pregnant with his 3rd grandchild and I really don't care to tell him. I was thinking maybe I'd tell him the other day because it was his birthday, but shocker no answer, no call back, no text. Am I wrong for not telling him? 
I have a similar situation with my sister. We don't really have any sort of relationship and she's impossible to get ahold, granted I know she works constantly, unlike our dad, but still. There's very little effort put in to talk to me or her nieces and I have tried to stay up to date with her. We're just not on the same page with our lives. So I guess my question is am I in the wrong for not really wanting to tell them? I'm not hiding it, but just not making a ton of effort to try and reach them to let them know.