(Reuters) - Bristol Palin, the daughter of former Alaska Governor Sarah Palin and an advocate of sexual abstinence before marriage, says in a blog post that her second out-of-wedlock pregnancy was "actually planned".

Just over a month ago, the former governor and 2008 Republican vice presidential nominee announced that her daughter's planned marriage to Medal-of-Honor winner Dakota Meyer had been called off.

"This pregnancy was actually planned," Bristol Palin wrote on Sunday in a blog post entitled "My Little Blessing".

"Everyone knows I wanted more kids, to have a bigger family. Believing I was heading that way, I got ahead of myself," she wrote. "Things didn't go as planned, but life keeps going. Life moves on.

"This baby is not a disappointment, and I cannot wait to be a mom times two," she wrote. Bristol Palin, now in her 20s, did not identify the unborn baby's father.

Her first pregnancy as a teenager gained widespread attention in 2008 when it was disclosed during her mother's campaign with Republican presidential nominee Senator John McCain.

At the time, Sarah Palin said her 17-year-old daughter would marry the baby's father, Levi Johnston, but the engagement was called off.

Bristol Palin, citing her experience as a teenage mother, has spoken out in favor of abstinence before marriage and is listed with a booking agency as a speaker on issues of abstinence.

(Reporting by Eric M. Johnson in Seattle, Editing by Ellen Wulfhorst and Ken Wills)