How do you know what is the right thing to do?

How do you know when you are truly ready to be done having babies? I cannot go on my instinct alone. Well, for one thing, in our house it takes the two of us to make that happen. R is so wanting another baby. I am so not. We have an almost 9 year old that still doesn't sleep all night most nights. My feelings are so mixed. For the time being we have agreed to disagree. It is really hard for both of us. I just cannot give him what he wants right now. It is not just about the sleep thing. Money is also involved. We would be paying a lot for 3 in daycare. Right now we pay just as much for M's after school care as we pay for D full time. D will be starting preschool in the fall (another expense). And it is not just about the money either. One big thing is my patience. I am not sure if I have enough to go around if we have another one. With having D in school and seeing the amount of homework involved with her only being in third grade, it is scary to think of what it will be like in a couple of years when there are two in school. Me quiting my job (as much as I would love to) is not a feasible option. I carry our health insurance, life insurance and my retirement. Going to part time sounds more and more appealing, but not sure how particle that is. I had a hard time with both of my pregnancies. I was sick everyday with M and developed toxemia and delivered her at 37 weeks. Not as sick with D, but my blood pressure was not controlled even with medication and they watched my kidneys closely. The only reason I was allowed to work towards the end of my pregnancy was because my OB was in the same building that I work in and he spoke with the doctors that I work for. I was under strict orders to be careful. And the hospital is attached to the same building I work in. I delivered him at 37 weeks as well. Even with all of this I still want that new baby smell, the new baby feel in my arms, etc. Not a decision that I will be making any time soon, but something that is definately on my mind.