Depends what you mean by "old". If you mean elderly then obviously you're not. If you mean "past it" then it might reassure you to know the average expecting mother is in her 30s now (in the UK). Even if you just mean "grown up", recent research [1] on brain development identifies adolescence as typically extending into the early thirties, with (brain) adulthood running from there to the mid sixties before even then only entering the "early aging" stage.

For my part, I'm a lot older than you and don't consider myself old. Indeed, I think prematurely thinking of yourself as old can be a pretty bad mistake, health-wise.

[1] https://www.nature.com/articles/s41467-025-65974-8

FWIW I doubt I'd consider you old were I to know your actual age. I still think I'm quite young