Will She Choose (Will of the Hearts Series #2) by Alyssa Ray-Bouman:
 
A story about SECOND CHANCES, TOUGH CHOICES, AND THE COURAGE TO FOLLOW YOUR OWN HEART

Callie finds herself standing at a crossroads with an impossible choice to make. With hearts on the line, will she have the courage to listen to her own, and take a chance on her happily ever after, or will she let love slip away?

Callie DuPonce has never liked surprises. Living in the Adirondacks with her friends and family, she has everything she needs. So when she found out she was pregnant this summer, it was enough of a surprise to last a lifetime.

But these things tend to come in threes. Her ex-boyfriend Parker—the one she never told about the baby? Yeah, he's back, and he's determined to make it work.

As if that weren't enough, Callie finds herself falling for her lifelong friend, Tom—the sweetheart sergeant who has loved her all along.

She was ready to take on motherhood with just the support of her family and friends. But now, she's torn between her first love—the man who broke her heart when he left—and the friend she's afraid to give her heart to, the one who has been there all along.