Surrogate

One moment, Carrie Williams is eight months pregnant and driving to meet her
husband Robbie. The next, a silver streak rushes into her car's path. Carrie
tries to turn the wheel, resulting in a horrific accident. It is in Carrie's
dying moments that she sees the alien, an explorer from a race who doesn’t
believe humans exist. After the alien almost collides with car, she senses the
small life form in Carrie's body and merges her form with that dying human body
to save a life, unaware how that single choice will change everything for both
races.