Weird feelings? Help!

I'm having a feeling that I want to get pregnant, although I'd be so shocked and so scared if I did. I keep having this feeling that I want to, and I want to speak to my SO but I think he'd freak out. He's mentioned before that he wants kids, but not any time soon. He says he would be happy if it happened accidently but he doesn't want to plan anything. What can I do? I'm too scared to talk to him, although I'm so broody! It's killing me! Help😭