Back and Forth

I suppose there comes a time in every woman's life when she tries to figure out if she wants children or not.  Call it what you want -- biological time clock ticking away, influence of friends and family, society's standards and so on -- but I can almost guarantee that just about every female has, at some point, thought about having a baby (or NOT having a baby).
Personally, I've gone back and forth on the subject.  I never really thought much about it when I was young, but once married life came around, it obviously came up from time to time.  As friends started having families, it was even more of a subject to think about.  I went through a period when I was so turned off by all the women around me who could only talk about their pregnancies and babies and cycles and strollers and sleep patterns (too much information, always) that I started wondering if I even wanted to have babies.  I went back and forth, making a pros and cons list in my head ("would have more money/free time if we didn't have kids... but how can you justify wanting more time to yourself versus having a family?")
A year or so later, I became pregnant (surprise!), and then miscarried.  After that, it was "all baby, all the time".  I wanted a child so badly it physically hurt.  I got to the point that I didn't want to hear about anyone being pregnant, didn't want to see any cute infants in strollers, and certainly didn't want to hear my mom say, over and over, "It will happen, honey.  It's all part of God's plan."
That almost sent me over the deep end.
After a few months of sort-of-trying for a baby and having zero success, I have to say I'm veering away from my phase of baby-mania.  I can't tell you why... is it hormones?  Is it my inner instinct to try to protect myself from another emotional letdown?  I have no idea.  All I can say is that while I'm still okay with being a mom someday, I don't have that same burning desire I did a few months ago.  Do other people experience this?  How do they cope with the ups and downs of the process?