Well, even in the case of the negative bloodtype, I would have to be pregnant first with a negative baby (as I positive) and then the body would build antibodies and attack the second baby (I am going into nursing school and we learned that in A&PII). So, if it were multiple miscarriages, I suppose it might be plausible.
Oh, gosh if I am miscarrying, I am going to need a lot of huggin from you guys (and from my church). My husband and I have never had a child. That would break my heart.