Where's a mother's love?

My mom wants nothing to do with me or my soon to be son because she wanted another child of her own & she wanted a boy.. Which is what my SO & I are having. She's so hateful towards us & I know pregnancy can sometimes bond a mother & daughter closer, but I now want nothing to do with her because I believe she's jealous of what I have. I told her she isn't going to be a part of my son's life. Is this too harsh?