"So here are the things you should all get straight before you continue to mock me, judge me, and talk about me. None of us are perfect," Bristol wrote in a blog post titled "My Little Blessing" on Patheos.com. "This pregnancy was actually planned."
Bristol had previously said in a blog post on June 25 that "this has been, and will be, a huge disappointment to my family, to my close friends, and to many of you." But in her most recent post, the 24-year-old daughter of former vice presidential candidate Sarah Palin says she does not regret this pregnancy and that she always wanted a bigger family.
"This baby is not a disappointment, and I cannot wait to be a mom times two. Tripp is going to make the best big brother!!"
Bristol also addressed criticism, saying that she was never an "abstinence spokesperson" and had only worked for The Candie's Foundation, a teen pregnancy nonprofit, when she was a teenager.
PHOTOS: Bristol Palin through the years
"I'm not 17 anymore, I am 24," Bristol said in her post. I've been employed at the same doctor's office for over six years now; I own a home; I have a well-rounded, beautiful son."
Bristol also stated that this pregnancy "is not the ideal situation" but that "life is important even if it's not in the most absolute ideal circumstance."
"This is more confirmation on what I've always stood for," Bristol said in her blog post. "I've always been pro-life and I am standing for life now. Deal with it."
Bristol gave birth to her and former fiance Levi Johnston's child Tripp Easton Mitchell Johnston in December 2008. In May, Bristol and Medal of Honor recipient Dakota Meyer called off their engagement. Bristol is also a former finalist on Dancing With The Stars.