Jenny,
I don't know what I am doing in this forum, since pregnancy doesn't interest me in the least. However, I happened to be on the home page and caught your post saying you were leaving so I immediately clicked on it, feeling sad at the thought of you leaving. But then I saw it was just this area.
I am going to give you information that may or not be helpful to you. But after reading your posts, it may be worth a shot. I know you know that I mainly talk about inflammation and the effect it has on the body...
My doctor has had many patients that have had trouble conceiving or suffer multiple miscarriages, or even have multiple in vitro fertilization attempts. before they came to her and she has helped many get pregnant. I remember your story well with the kids and saw how stress made you sick. And I wrote to you about how stress raises the inflammation level in our bodies and makes us vulnerable to illness.
Well, that same inflammation can keep you from getting pregnant. My doctor does several things -- things that I have already talked about in the other posts. She gets the inflammation reduced overall. If you are sick all the time, (in other words chronically) inflammation caused by allergens, irritants, and chemicals, also causes inflammation in the uterus and can make it hard for the embryo to implant and if it does, it makes it hard to hold on to it resulting in miscarriages. ( I am not a doctor so bear with my bad layman's descriptions).
I know for a fact, that for example, my doctor once was treating this new patient (one time she was the appointment before mine). She was seeing her for some lung problem but had mentioned that she had tried multiple in vitro attempts which cost small fortune. My doctor said that she had pretty good success in helping people like her who have no particular physical reason preventing pregnancy. First she got her to reduce the triggers that caused the inflammation. (her lungs got better too, of course). Then on the day she was to do the In Vitro, my doctor gave her a cortisone shot, to reduce the inflammation even more. Then she went to have the procedure done. And got pregnant like many others.
You can reduce inflammation in a lot of ways. Then you should google and see if you can find a doctor who will work with you in this fashion. My doctor said she knew of another doctor who did this also -- but most doctors probably wouldn't even know to do this. Inflammation is just starting to be studied in depth.
If this seems wrong to you -- well, I gave it a shot. You are such a sweet, caring person (I remember how you sacrificed for those kids).
Best of Luck to you.