His Rejected Luna Strike Back by Jessica Molly at Inkitt

Summary

After a false accusation, Emily was expelled from the Crimson pack and rejected by her mate, the Alpha. Pregnant and desperate, she found refuge in the hands of the Lycan Alpha.Years passed, and the Lycan Alpha passed away, leaving Emily as the new Alpha of the Lycan pack. Now, she returns seeking revenge against the Crimson Alpha for the pain he caused her.