I don't have children. I have had two miscarriages. The second was likely fathered by my boyfriend, with the consent of everyone involved.
I wrote a bit about it here
I have now resigned myself to never bearing children. Which does not mean that I don't still have the urge to do so.
Sourgirl, I would also point out that, for those of us who have never had children, a miscarriage also brings the grief of missing out on motherhood itself
as well as the loss of that particular child and the hopes and dream for them.