"We found out in June," Csincsak, the 31-year-old former fourth-season The Bachelorette winner, toldUs Weekly. "We were very pleasantly surprised."
While the couple is thrilled to have a baby on the way, Lueders -- a former thirteenth-season The Bachelor bachelorette -- has had a tough time with morning sickness.
"Ann has had very bad pregnancy sickness. Our doctor told us she has one of the worst cases he's ever seen!" Csincsak said, adding they've needed help from family and friends to maintain their clothing and public relations companies in addition to caring for their two-year-old son Noah Theodore.
"We have had to call in the reinforcements. I called her mom and dad, and they have been staying with us for the past month, helping to take care of Ann while I look after the businesses and run Noah back and forth to school."
Csincsak and Lueders welcomed Noah in February 2011, and Noah apparently can't wait to become a big brother.
"Noah loves babies, so we sat him down and told him there is a baby in mommy's tummy!" Csincsak told Us. "He just looked at us and smiled! He is still to young to comprehend the big picture but he loves babies."