Gap year concerns

Ok I’m a bit prone to overthinking everything. But I can’t help but think that if I take a gap year (and I doubt I will take a 3 year degree and be out by 22, I’ll probably do a placement year or masters/ PGCE too) I will probably be about 24 by the time I finish uni. It worries me that after working on my career and earning enough money to afford a house/ children I will be too old to have kids. Maybe I am catastrophising the situation but I keep thinking what if I take this gap year (the main reason is because I’m not 100% sure on what course to do) and it literally ruins my main life goal of having a family. Do you think if I left uni at 24, it gives me enough time to work on my career to be ready to have kids in my early 30s?