It is pretty strange though.
I don't see how, It is the biological end goal for sex. Pregnant women are still beautiful and they are doing an amazing thing by creating another life. Not to mention it's a common fetish so by default it's not strange some people just might not like it which is fine. but it is no more strange than bdsm or vanilla porn. Aside from that kink shaming is wrong except for the truly illicit stuff like snuff or rape etc, that kind of stuff is just vile. we can all have different tastes; what would be truly strange is if we all liked the same things.
Pregnancy is indeed the biological end goal for sex but I don't think attacking people who criticize your fetishes is the right thing to do. You can have your fetishes and others can have their opinion on such fetishes. I think having a pregnancy kink is weird, I'm allowed to have that opinion and I am allowed to share my opinion, no amount of "it's a common fetish" is going to change my mind. Even though foot fetish is one of the most common, some people still think it's disgusting and I respect their opinion. I doubt you have to protect your own fetish from people that think it's disgusting by saying it's a common fetish and saying it's not strange, because for some people it is strange and it's their opinion and you can't really change that.
So if you think pregnancy is hot, I can't agree with you, but I can respect your opinion, since everyone has their own taste.