I like PSteve's advice to be a teacher and work out some of the maternal instinct that way.

Parenting is definitely hard, and the last thing you want to do is make a baby with a partner who doesn't want to be a parent. That's particularly unfair to the baby itself. I've known plenty of people who've come around on the subject of having babies later in life, so I hope you'll take the wait-and-see approach for the future but take definite steps now to prevent the if-it-happens-it-happens eventuality. Accidental babies are a set-up for disaster, for the parents and especially for the babies.

Children deserve to be born to two committed, in-love, settled, stable people who both feel strongly that they want children because they like children. Even when they're born into those circumstances, they absolutely turn your life upside down. It's a huge step, and far more people need to enter into it with great caution. The thing about parenting--and no one who doesn't have kids can really even begin to fathom this, although childless people will assure you otherwise--is that it is literally a 24-7 and 20 - 25 year proposition. The responsibility is constant, unrelenting, and overwhelming. If you think you're ready for it, trust me, you're not. Just spend 24 hours with a mama of a newborn, a small infant, or even a toddler or small pre school-age child. That will encourage you to keep using contraception and continue to have fun being young and single and free!