Maybe in Another Life by Taylor Jenkins Reid

Hannah Martin is a bit of a nomad. She can't seem to settle in once place. Since graduating college she has jumped from one job to another. She is 29 years old and still have no idea what she wants to do with her life. She returns to her hometown of Los Angeles and moves in with her best friend Gabby. They go out to a bar and run into Hannah's ex-boyfriend Ethan at the end of the night she needs make a decision. Will she leave with Ethan or go home with Gabby? The decision she makes will result into completely different circumstances. 

The story unfolds into two different realities that run concurrently. One in which she leaves with Ethan and the other where she goes home with Gabby. The parallel universes each have their disadvantages and advantages. Each chapter flips back and forth from one version of Hannah's life to the other. The storyline is done in a seamless manner which keeps you on the edge of your seat wanting more, more and more!

I have come to really enjoy alternate timeline stories and Taylor Jenkins Reid doesn't disappoint. This book is clever and entertaining.