Justin Timberlake confirms wife Jessica Biel's pregnancy with adorable birthday photo

Justin Timberlake celebrated his 34th birthday on Saturday by confirming that he and his wife, Jessica Biel, are expecting a child via an adorable photo on social media.

"Thank you EVERYONE for the Bday wishes!," he captioned the photo on Instagram. "This year, I'm getting the GREATEST GIFT EVER. CAN'T WAIT. #BoyOrGirl #YouNeverKnow #WeDontEvenKnow #WeAreTakingBets"

Biel was photographed with what appeared to be a growing baby bump earlier this month, but rumors about the couple's pregnancy started as early as Halloween of 2014. The editor-in-chief of InStyle magazine, Ariel Foxman, tweeted "Congrats @jessicabiel on your impending motherhood. Looking forward to the red carpet maternity style pix to come." That tweet has since been deleted.

In December, former N'Sync member Joey Fatone told In Touch that a little one was on the way, saying that Timberlake "told me a while ago, and I kept my mouth shut. But now I can talk about it!"

Timberlake and Biel tied the knot in Oct. 2012 in Italy.