Heartache

So I am in another one of my little depressions about wanting another baby. I go through this often, very often. I see a baby and my heart aches, I truly want another baby. I often wonder why it is that so many women (girls) can have as many children as they can, and should not even have one. Why is it that many people like me, who want children so desperately, can provide for, give lots of love, wonderful family, etc., can't? I don't understand. It is not fair. I know life is not fair, all too well. But this, is a constant heartache.