I think we get to choose our general circumstances, like what family structure and country we wish to be born in, and what time in history. We can specify whether we are male or female, gay or straight, and our overall intelligence.

But from the moment of birth on, I think free will takes over. There is no plan, although there might be an overall direction, and critical signposts. Wayne Dyer used to say in his books that, before he was born, he wished in his next life to be more autonomous. So God said, "Well, then we'll put your little ass in an orphanage for most of your childhood, so that you can learn to become self-reliant."

Some thought on when the soul enters the body. Some believe that the soul enters with the first breath. Many doctors have tried to explain the feeling they get when a baby takes it's first breath. This would be an indication that the soul does enter at the first breath. If this is the case, a soul is waiting or has chosen the family, parents, circumstances, environment that will give the life lessons that need to be learned in that particular lifetime. To answer your question, yes, we choose the physical body that we will infuse with our soul essense before we are born.

we one with our mothers until the umbilical cord is cut after that we are ourselves before that we are apart of our mothers body/being.so I would say its that moment that we Are

Apparently we fear birth as much as we fear death :) Fear of change?

What if our destiny is to be re-united with God, but we cannot do so until we make right choices. We can choose to re-unite or not.

I was shown who my daughter was before she was born (in a dream) - when she was three, she actually told me who she was. As an adult she has no recollection of that event.