Us Weekly confirmed the 26-year-old television personality called it quits again with Jordan after reconciling in November.
The Ashley's Reality Roundup said Messer and Jordan broke up about two weeks ago. Sources said Jordan has been trying to win Messer back.
"When someone shows you who they are, believe them the first time," she quoted.
Messer followed up Thursday with a message about learning and growth.
"So thankful for this beautiful journey that we call life!" the star wrote. "My thought of the day... Everyone comes into our lives for a reason, a season or a lifetime. I'm thankful for everyone I've journeyed with and continue to learn and grow."
"When we can live in the present with appreciation there's no room for judgement. Some things are just not meant to be and that's ok," she said.
Messer is parent to three daughters, 9-year-old twins Aliannah and Aleeah with Corey Simms and 6-year-old Adalynn with Jeremy Calvert. She came to fame on the MTV series 16 & Pregnant before starring on Teen Mom 2.