I have to agree w/ Terrilacy. Kids are not something you try out.
I have heard lots of people say, "Oh, it's different when it's your own." Maybe it is for some people, sometimes. There are plenty of mothers out there who are neglectful, abusive, and just not interested--including my own mother, who didn't find it in her heart to even like me a little bit until I was a grown adult--and I'm sure everyone told THEM that it would be different with their own.
Kids are WORK. You might not mind doing work for your own kids, much in the same way that you don't mind washing your own dirty underwear, but that doesn't change the basic fact of having to do the work. It just makes it somewhat less ooky. I never did meet a parent who honestly liked cleaning up vomit and poop, only those who minded it less when it was their own kid's. However you look at it, it is tons and tons of work--much of it tedious, boring, mind-numbing, frustrating and annoying. If it was fun and joyful all the time, everyone would want to work at a day care center for $7/hour. While some women love that type of work, lots don't. I think it takes a special kind of person to really love that work, just like it takes a special kind of person to be a nurse, doctor, algebra teacher, nuclear physicist, etc.
You are not going to get the kid you want. If you assume that from the get-go, that you will not get a mini-me, I think you'll be much better off. My mother was sure she was going to get a mini-artist who would travel and do all the things she had longed to do with her life and career, and was NOT happy to get a geeky, introverted scientist. DH's dad was sure he'd get a Young Republican, and got a liberal-minded tattoo artist. I know lots of atheists and Pagans and Buddhists whose parents raised them as devout Christians, lots of devout Christians and Young Republicans whose parents are hippies, and so on. When you decide to have a child, by whatever means, you are spinning the roulette wheel. Don't place your faith in genetics or your awesome parenting skillz to get you the child you want. What you want doesn't matter, you get what you get.
Kids cost MONEY. Lots and lots of money. I'm not counting the cost of college, I'm counting the cost of extra rooms in the house/apartment, extra clothes (you won't have hand-me-downs with the first kid), extra room in the car, extra car trips to take Junior to soccer practice or ballet or what have you, field trips to wherever, babysitting, day care, and so forth. You can economize on that...up to a point. But all kids need basic care, and even pretty basic food and clothing for one human being for 18 years costs a pretty penny.
Someone already mentioned health, but even a very healthy child needs many more regular pediatrician visits than a healthy adult. My co-workers with small children use ALL their vacation and sick days to take the kids to the doctor for this, that and the other. Between pre-natal, post-natal, well-baby, vaccination schedule, semi-annual checkup, school-entry checkup and actual injury/illness visits, they are rarely at work. If you're not especially ambitious, maybe that's OK with you. But it sounds like you sure would not be happy to give up all your sick time and vacation time for someone else--and have to come to work anyway when you yourself are sick.
Kids are a strain on your relationships. All relationships. Your friends, your family, your spouse, all those relationships will change drastically and you will lose some. Some friends will be frustrated that you no longer have time for them with all the work you do for the child, or that you no longer have time for the hobbies/interests you had in common with them. Some relatives will suddenly take a prurient interest in your girly bits that is really none of their business, but they will feel entitled to it. You will find you disagree with your spouse on various minutiae of child-rearing, and you won't have as much time for your spouse because both of you will be spending 90% of your non-working time parenting.
And that's all assuming you get a healthy, relatively normal child. Lots of people don't. All of the things I've described above are what normally happens when people have children--not exceptions at all. I don't believe that having children is a job that should be taken on by anyone who isn't actively volunteering to do all those things.
You need to talk with your spouse in a very serious way and get it through his head that you really mean this and are serious about your non-interest in children. Quite honestly, I think that the decision of whether or not to have children is a marital deal-breaker, and that most people are better off finding someone they can live with happily who shares their feelings on children rather than trying to change the other person. Lots of people go the "oh, you'll change your mind" and "all _______ love children!" and "well, you'll love it once it gets here" route, and find that in fact they didn't change their minds, that child-rearing was just as awful as they had imagined (or worse), that the magical maternal hormones never did kick in, that they did not love the child when it got there. It's just not socially acceptable for women to say out loud, "being a mother really sucks and I hated every minute of it. It's poop-work, and you couldn't pay me a million dollars a second to do it again." I know a lot of men cannot imagine a woman who doesn't love children, and they have this idea in their heads that All Wimmins Lurve Baybeez; don't know if your spouse is in this camp, but you might have a hard time dispelling this notion, is what I'm saying.
Good luck to you. I think you will need it. Personally, I'm in your camp--I've never liked kids in the least, even when they were related to me. Just so you know you're not alone.
