The Barren Alpha Knocked Me Up with Twins

Chris has left home and taken work at a bar. She was badly treated in her family's house before she went, and her stepmother runs that house. One night at the bar she is drugged and spends the night with a man she does not know. He is Kaelen, the strongest Alpha of his werewolf clan, and he has a fertility problem his grandfather has been trying to solve by arranging him a marriage into Chris's family. Chris is pregnant afterwards. Kaelen's assistant works it out and tells him. Chris goes back to the house to borrow money from her stepmother and is laughed at for asking. Kaelen turns up, gets her out, takes her to a hospital and tells her to keep the child, saying he will protect her. He then goes after the families of the people who had been treating her that way.