Bristol Palin has revealed the sex of her baby.

The 24-year-old daughter of Sarah Palin announced Monday she has a baby girl on the way although she's still declining to name the father.

"7.5 months with my baby girl," Bristol captioned a photo of herself cradling her baby bump on Instagram.

Bristol, an Alaska native, announced in June that she's expecting her second child.

The news came about a month after Bristol announced she and her ex-fiance Sgt. Dakota Meyer, a 26-year-old U.S. Marine veteran who had received the Medal of Honor in 2009, had called off their engagement. Bristol had taken everyone by surprise when she canceled the wedding just days before she was set to walk down the aisle and offered a very vague explanation.

Bristol already has a son, Tripp Easton Mitchell Johnston, from a previous relationship with her high school sweetheart and ex-fiance Levi Johnston. They welcomed Tripp in December 2008 when Bristol was only 18-years-old, and then she became a teen pregnancy prevention spokesperson.

Bristol and Johnston had been engaged twice before officially calling it quits in 2010. Johnston now has a daughter, who was born in September 2012, with his wife Sunny Oglesby.

Bristol competed on the eleventh season of Dancing with the Stars back in 2010 and reached the finals with pro partner Mark Ballas, finishing in third place. In November 2010, she appeared on TLC's Sarah Palin's Alaska documentary.

Bristol then starred in Bristol Palin: Life's a Tripp on Lifetime in Summer 2012. She most recently competed on Dancing with the Stars' Fall 2012 All-Stars edition but was sent home in the fourth week of the fifteenth-season competition.