limbo

I don't really know what to say, so I am just typing and hoping something will pop up. I lay in bed at night and process everything and think of stuff I want to write, but then when I get up in the morning I can't remember.
Right now I am still in the limbo of "to try again" or "to not try again". I woke up a couple of weeks ago and felt like I was really ok with not having another baby. My boys are more than a handful, they are just starting to be independent, we can go out and do fun things together, babies are exhausting, I don't know if I can handle 3 and I know that Mark really doesn't want another one. Then, the boys start asking when we are going to have a baby and talk about how much they want one. I was filling out a medical history for Danner yesterday and it was asking about birthweight, Apgar scores and developmental milestones so I got out the baby books. The boys and I sat down and looked at all their newborn baby pictures - probably not the smartest choice! Every month a few days before AF, the anxiety sets it and I start to hope that maybe I am pg even though we are not trying and I know that I'm not. It's driving me crazy!
Here are the God questions I am working on right now - I know that God didn't cause this (I need to post on that later, but it's a long one) but why didn't he prevent it? I prayed for a full term healthy baby and I truly had faith that it would happen. It didn't. We can pray for healing, but why is it that sometimes He doesn't heal?
The Bible says he will give you the desires of your heart and what you ask for in prayer which leads to a whole another set of questions. I have met so many women that have prayed and prayed and want nothing more than to have another baby, but haven't.
I know God will help me find answers to these questions just like he has to all the other ones I've had, but I just thought I'd share them with you and see if anyone has any input.