The stage that I am in has been investigated by anthropologists who coined it "liminality." As humans move through major stages of life, many cultures (if not all) designate a period that is in-between stages, marked with a set of rituals (rite of passage). One obvious example is adulthood (often for males), and another, death. When a person enters this in-between stage, that person belongs to a transient stage, often isolated from society, and the normal social rules do not apply. To my knowledge, not much is studied about the phase that I am in: I am neither a mother nor a non-mother. I am pretty much removed from the normal social environment (since my maternity leave started), and I am definitely treated differently.
At 36 weeks, I feel that I am verging on the cross-over. I am called a "mom" from time to time, although it is clear that I am not one yet. I am a non-mom and a mom at the same time. What do you say, Dr. Schrodinger?