WARNING: We're about to reveal one of the biggest Big Bang secrets the series has ever had. If you do not wish to know which couple has a bun in the oven, leave now! For everyone else, prepare to swoon…

Oh, baby!

The Big Bang Theory just dropped an unexpected bombshell on us in tonight's Valentine's Day episode: one of our leading ladies is expecting!

Now that each of the Big Bang ladies are officially in a coitus-filled relationship (way to go, Amy and Sheldon!) all of our gals -- Penny, Bernadette, Amy and Raj's girlfriend, Emily -- are officially on the maybe-baby list.

So, which one of our four geek-tastic couples will soon be having a new addition? Say congratulations to…

MORE: The Surprising Secret Behind Those Romantic 'Big Bang' Moments!

Bernadette and Howard!

Our first Big Bang couple to tie the knot is also the first to bring a little one into our take-out-loving group of friends.

But there's just one catch before a little Rostenkowski-Wolowitz will enter this TV world: Howard doesn't know that his pint-sized wife is expecting just yet!

MORE: 6 Reasons Why Sheldon and Amy's First Time Was Worth the Wait!

In the love-filled episode, Bernadette said the news out loud after Howard had already left the room. "We'll find another time to tell him that I'm pregnant," she whispered to a bunny they rescued from their new hot tub.

Press play on our recap video above to watch the sweet surprise for yourself!

The Big Bang Theory airs Thursdays at 8 p.m. ET/PT on CBS.

Were you shocked to discover that Bernadette is pregnant? Who else was hoping Amy would be the one expecting a baby? Share your thoughts with @LeanneAguilera on Twitter!