No, it's not just you. I'll be 44 in four months, and I agree with you.
Let's say it takes you a while to get pregnant -- being past your prime baby years, that's likely -- so you'd likely be 46 (or more) by the time the baby is born. So that makes you 51 when your child starts school, 55 when they ask you to coach Little League or sleep on the ground for a Brownie scout sleepover, 61 when you're teaching that child to drive and dealing with teenaged issues, able to begin drawing social security while the child's still in college. And that's assuming that everything works out well medically.
I think it'd be an uphill battle in many ways. At some point people will begin to assume that you're the grandmother (either an involved grandmother or the parent of a child unable to take care of his own children). Though no child can count on having his or her parents there for him when he graduates from college, when he marries, and when he has his own children, your child would have even less chance than others to have you there for support. How do you stand financially in retirement preparation? Many 40-somethings are just getting serious about it; if you're in that boat, it'd be awfully hard to do that AND take on the financial aspects of raising a newborn.
I understand perfectly that our society has decided that everything anyone wants to do is perfectly fine these days, never mind the consequences . . . but I wouldn't do this.