Frances Belmonte and her husband of three years will have their first baby in August. They will be new parents at age 37 and are fine with it.

"There were points in time where we weren't even sure we even wanted to have kids," she told me in an interview. "We had lots of conversations about it and thought about pros and cons."

Con number one: "Kids are just so freaking expensive," she said while laughing. "Between us moving around so much and not having much money, it just didn't make sense for us to even try."

Belmonte and her husband, Ben, have lived in their Washington, D.C., apartment for two years, after a nine-year courtship that had them hopping from Baltimore to New York to Pittsburgh to New Jersey. Unlike previous generations, millennials have found that a house is out of the question because of student loan debt. Also unlike previous generations, it was her career they followed, not his. She got her bachelor's degree in biochemistry while he received his degree in political science and criminal justice, then went for the ride as she studied for a master's and a doctorate in toxicology. Being an Air Force brat, he had no problem moving from place to place, she said.