This is actually so common that it's considered just a variation of normal. I think about 30% of women or something.

I have one It isn't related to miscarriage in any way so please don't worry about that - miscarriages, unfortunately are also reasonably common so women with a retroverted uterus are going to experience them, just as women with an anteverted uterus do.

I'm sorry your little one was lost, much healing to you hun