Dykstra, an infielder for the Washington Nationals, asked the Sopranos star to be his wife on Jan. 27. Sigler, 31, shared a picture of her engagement ring via Twitter the following day.
This will be the first child for the couple, who went public with their romance in March 2012. It will be the first marriage for Dykstra, 23, and the second for Sigler, who was wed to her manager, A.J. DiScala, from 2003 to 2005.
"Jamie couldn't be happier. Cutter is the perfect guy for her," a source told Us shortly after the couple got engaged. "Although they have only been together for a year, they both know that this is it for both of them. They are both on cloud nine as are their families and friends."
Dykstra certainly agrees. "Thanks everyone for all the love! Means so much," he tweeted Jan. 29. "Me and Jamie-Lynn are still on cloud nine!"