Bumped by Megan McCafferty

WARNING: May contain spoilers! 

When a virus makes everyone over the age of eighteen infertile, would-be parents are forced to pay teen girls to conceive and give birth to their children, making teens the most prized members of society. 

Sixteen-year-old identical twins Melody and Harmony were separated at birth and had never met until the day Harmony shows up on Melody’s doorstep. Until now, the twins have followed completely opposite paths. Melody has scored an enviable conception contract with a couple called the Jaydens. While they are searching for the perfect partner for Melody to bump with, she is fighting her attraction to her best friend Zen, who is way too short for the job. 

Harmony has spent her whole life in religious Goodside, preparing to be a wife and mother. She believes her calling is to bring Melody back to Goodside and convince her that “pregging” for profit is a sin. But Harmony has secrets of her own that she is running from. 

Queens of All the Earth by Hannah Sternberg

Warning: May contain spoilers!

As her freshman classmates move into dorms at Cornell University, Olivia Somerset suffers a nervous breakdown. When months of coaxing and analyzing fail to rouse Olivia from her stupor, big sister Miranda decides the sisters should fly off to Barcelona for some "vacation therapy." 

When a mistake at their Barcelona hostel leaves the Somersets in a large co-ed dorm room, Olivia and Miranda are saved by kindly Mr. Brown and his son Greg, who happily volunteer to surrender their private room. But while Olivia feels an instant connection with brooding Greg Brown, Miranda sides with fellow guest and cocky American travel writer Lenny: 
The Browns are just plain weird, and must be avoided at all costs.

In the midst of urbane Peruvian priests-in-training and Scottish soccer fans, from the shops of La Rambla to the waters of the Mediterranean to the soaring heights of Montjuic, Miranda works to protect her still-fragile sister while Olivia struggles to understand her burgeoning adulthood, her feelings for Greg, and the fear that makes the next step in her life so impossible to take.