Is it bad that when my bf (M20) and I (F20) talk about having children in the future, it’s vague sometimes and I have no idea if he means our children or just his?

We’ve been together for about five months now and I like talking about my future with my partners very early on because I date to marry and not the other kind of bull. It’s kind of confusing I guess, but sometimes we do say “our kids” and whatnot, but it’s kinda usually just me, yet he does agree but I feel like he’s just saying it because duh, I said it. And I have no idea how to feel about it. Sometimes, when he does talk about it he says, “my children”. Like for example, he said this evening that he wanted his children to excel at something kind of sport. I agreed with the statement but damn, ‘his’ children? Maybe I’m just overthinking. But it sticks with me sometimes. No idea of it’s bad or not.

TL;DR My bf sometimes says “my kids” instead of “our kids” when we talk about the future, and I’m not sure if I’m overthinking or if it means he doesn’t see me in it.