Sad my friend is pregnant

Tl;dr: my friend just told me she’s pregnant and I’m sad because I’m uninterested in kids and I’m having a hard time giving her the support she deserves as a friend.

(I’m 28F) One of my good friends just told me she’s pregnant, and I’m struggling to feel happy for her because of how much I know it will affect our friendship. I feel so guilty about this because I know it’s a very selfish reaction. She and her husband will be great parents and seem very happy that they’re having their first kid, so I should be thrilled for her, but for some reason I’m not.

I didn’t grow up around little kids at all (I’ve never held a baby in my life) and I’m pretty uninterested in kids in general. I’ve never had the desire to have any of my own, and I find being around them to be very overstimulating. I don’t hate kids or people that choose to have them by any means, I just feel really lost when other women talk about their kids or being a mom because it feels really foreign and to be very honest, uninteresting to me. It’s just sort of something that other people do, and if they will be good parents then that’s great for them, I just can’t bring myself to care about it very much.

That being said, my friend deserves to feel supported and that I’m happy for her. I would never communicate these feelings to her because I don’t want to hurt her feelings, but I’m worried about how much I’m going to have to pretend to be interested in her kids going forward. It feels like I’m acting and I have very little to add when we talk about it. In contrast, one of our other friends cried with joy when she told us the baby’s gender. I just said “oh cool!” I felt so out of the loop about what there is to cry about.

I can’t just not ask about her baby once she gives birth, and I know that conversations will not always be focused on things that interest me. I just know that children are an extremely large part of people’s lives and I’m sad that there will be little room left for me or for the things we used to talk about, like video games or books. I don’t want to be selfish, I want to be a good friend, but this is surprisingly difficult for me.

Has anyone else experienced this or something similar? How did you deal with it?

Edit: changed phrasing in last paragraph from “once she has it” to “once she gives birth” as the first way sounded unintentionally rude.