Vanessa and Nick Lachey are having a second baby, and it's a girl!

While celebrating their third wedding anniversary on Tuesday, the Lacheys decided to announce their new baby news to their Twitter fans.

Nick tweeted while Vanessa retweeted the message, "Can't think of a better way to celebrate 3 years of marriage to my beautiful @VanessaLachey than this! #family,"

Nick also included a photo of his and Vanessa's 1-year-old son, Camden running in the sand that included the phrase, "It's a girl."

Following the birth of their son Camden, E! News reports that Nick was eager to continue expanding their family while Vanessa was content on waiting a while.

"Well, I'm not past the exhaustion point and I could go a minute with just the three of us right now," Vanessa explained to E! News. "But I was telling somebody earlier today that men have a biological clock. [Nick]'s like, 'Baby, I'm 40. We gotta get it moving.'"

In addition to celebrating their baby girl, the couple also celebrated the love they shared with one another on their wedding anniversary. Vanessa shared a photo on Instagram from the couple's wedding day along with a heartfelt message expressing her love for her husband of three years.

"July 15, 2011... I got to marry the best thing that has ever happened to me. He has shown me how to Love, Trust, Respect, Compromise, Grow, Dream, and truly become a Family. I am grateful everyday for the life we are creating... together. And can't wait to see what's next! #HappyAnniversary," she wrote.

On Wednesday, a day after his anniversary, Nick continued on with the baby news excitement and thanked those who wished his family well on the new baby. Nick tweeted, "Thanks for all the well wishes on our upcoming baby girl. Camden is taking boxing lessons now so he can help daddy fend off the boys!!"