Then it comes down to either:
A. Get married once you're ready to immediately have children, or
B. Get married because you can't control your sexual desire, use contraceptives/abstinence to prevent pregnancy while you're still not ready to bear children
?
This is greatly disputable. I want kids but I don't want to have them early in my marriage because I know there are so many things to adjust between my husband and I, from two individuals into one. Adding a child into this scene is IMHO not the wisest thing to do. But to do abstinence is probably not the wisest thing to do either. Then there are contraceptions. Although I heard those using contraceptive and then wanting to conceive have a hard time conceiving, but I also know first-hand stories of those still under contraceptive but still conceived anyway (in their amazement -- and shock).
So, IMHO, I have nothing against the contraceptives because should God will one to conceive, nothing can prevent Him from doing it: not even contraceptives (ref: Mary and Elizabeth).
B for me.