I know I will be crucified for this, but I am not saying that what Abhi did was right, he practically ruined her life, but still she is pregnant with his baby. By getting abhi caught by the police, Pia might get her revenge, but by the end of the day, she will be alone.
But if Abhi is bad guy and have some hidden agendas along with his father, and He is a villain in some other way too, than she should leave him.