i am so glad you joined the group, i hope you find the comfort here that i did when i joined.
I had one miscarriage....that was many many years ago, so i can't attest to multiple ones, but i do recall seeing some threads about miscarriages. So, i am sure that others will be along very soon and they will be able to share stories and drs. explanations with you.
good luck....so glad that you have such a precious step-son...he is very lucky to have you.