Before ever getting pregnant, could you see yourself as a mother or even pregnant?

For as long as I can remember I have ALWAYS wanted to be a wife, mother and have a traditional household(husband provider and I caretake). Well I have the traditional relationship. I baby sit and contribute to the bills and pay for our food but my boyfriend pays the rent. Sorry back to my point... I have always wanted kids but I can't see myself pregnant or having a child. I have taken care of other kids (6+ kids at a time) since I was 8years old (now almost 25). I just have nurturing blood. For Peas and Rice's sake I even had to raise my own mother since I was a child and I long for my own family but I dont understand why I don't feel that it'll ever happen for me.