The 20-year-old "Teen Mom 2" star is expecting her third child, her first with new husband Jeremy Calvert. She's due this winter.
"Jeremy and I are excited to be adding a new addition to our family," Leah says to Us Weekly. "Being a teen mom was difficult, but I'm older and in a different place now -- married to Jeremy and excited for our family to grow."
Messer has twins Ali and Aleeah with ex-husband Corey Simms, who she divorced in April 2011. Leah tied the knot with Calvert this past April.
"Ali and Aleeah can't wait to meet their new brother or sister," Jeremy tells the mag.
So far it seems like the reaction has been good, as Leah tweeted last night "THANKS SOOO MUCH EVERYONE! #PositiveTweets makes this momma soooo happy!!! @Calvert505 are in such a good place! Love all of you!"
Leah reportedly suffered a miscarriage with the couple's first pregnancy in January. The emotional experience is expected to be shown on Season 3 of "Teen Mom 2," which kicks off November 12.