So, tone matters here, he's either really creepy, or he was just joking around.

He's just talking to your uterus, trying to curry favor with it. Also, he's seeing if it's a suitable place to deposit his seed. Seems totally normal.

Make sure you get on birth control ASAP. He intends to make you pregnant if you stay together. That’s not a good idea.

Someone else in the comments mentioned context and I complete agree with them, I'm ADHD/Aspergers and I even know that that's either a joke, or such a red flag you gotta GTFO there faster than road runner.

if it's a joke it's a bad one, if it's not he's either stupid or spends alot of time outside your window with his pants down, either way walk away

Run like hell. This is NOT normal. This is NOT okay. And for the love of God, do NOT sleep with this creeper.

On response to everyone else's comments, I would personally just say to talk to the guy. If he sees children in his foreseeable future, discuss that. Explain your side of things, whether or not you want them now or later if at all. If you're thinking about a relationship with him, it's definitely worth talking about. Communication is the key to everything.

Run. Run fast. Run far.

RUN.

If that's not a red flag then I don't know what it s.