This film was on Ch 4 in about 1984-85. Based in France I think.
Rich kid steals fathers car and runs away. Ends up with a young girl living in a cottage. He gets some fish by waiting for the fishermen to leave the small fish that wont sell (there were 3 small ones). The boy and girl are hungry. They end up having sex and she gets pregnant. He gets himself on his feet and gets a job picking and spraying grapes. He buys a childish book about pregnancy and birth and the girl has the baby. They bring the baby up and have are having a very happy time if it.
At the end the boy is found by his father /people representing his father, who are looking for him and they drag him in to a car and speed away. That's the way it ends!