I have a friend that had this happen to him several years ago. He dated this girl for a while, they broke up and he never heard from her again. That is, until 5 years later they came looking for him for child support. That's right, she kept it from him for 5 solid years. So...he had a DNA done and sure enough it was his. He hired a lawyer, private detective and found out quite a bit about his ex.
He counter sued, won full custody of HIS child and told her to beat it.
I like a good ending.