How to make it clear to men I don't want to date (be a girlfriend) for too long without sounding desperate?

I'm 22, single (just finished college), haven't been in a relationship yet and honestly time is precious to me. I'm not religious nor care about it. I just don't want to waste my time.

I don't want to give myself, invest too much time (4-6 years) with someone I'm going to break-up and then have to start all over. It's going to be harder by then. This might sound silly but I would like 3 children and my first one between ages 24-26, not in my 30's.

I know very well men don't like being pressured into commitment but here is the deal... if I let him take all his sweet time and wait for him to be ready then that'll be within 5-10 years and I can't wait that long nor want to. How do I make this clear to men without sounding desperate? What should a woman do if she wants kids when she's still in her good years?

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+1 y
I know how lovebombers and PUA sound like. I actually don't understand how a woman isn't already bored after 2 years of ''one day we'll have a family, I love you till the moon and the stars''. I'm getting out if I don't see anything happening soon.
How to make it clear to men I don't want to date (be a girlfriend) for too long without sounding desperate?
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