It wasn't the reaction you'd expect from granny after she gets her first glimpse at her new grandbaby.
"Oh my goodness!" she exclaimed.
And she's not alone. The reaction of the baby's other grandma was, "You guys are not joking!"
She was in utter disbelief! And the baby's aunt said, "Oh my God!"
They were all stunned.
Even the baby's parents, Kyle and Danielle Williams, did a double take when they first saw their newborn.
Danielle told INSIDE EDITION's Steven Fabian, "I was shocked, to say the least."
But why? What was wrong with the baby? Absolutely nothing. He's a healthy baby boy, perfect in every way. Trouble is, he was supposed to be a girl, guaranteed.
Why were they so convinced? Because of a sonogram image that was taken when Danielle was four months pregnant. The technician assured her that it was a girl.
Fabian asked, "What went wrong with the sonogram?"
Kyle explained, "We were told it wasn't the best picture when she printed it for us, but she assured us she saw at the very beginning of the ultrasound that it was in fact a baby sister for our daughter."
Naturally, Kyle and Danielle shared the happy news with the whole family and of course, everyone bought pink gifts.
Watch this other couple's baby surprise.
Then, came the big day. Danielle gave birth last week.
"You're there thinking, here she comes. Oh, wait...it's not a she," said Fabian.
He recalled, "I kept looking back and forth to my wife, not saying anything to her. She frantically asked me, 'What's wrong? What's wrong?' and all I could say to her was, 'Well, there's a bit of a surprise.' "
They had a lot of fun taping everyone's reaction to the surprising news!
"It's a boy? Oh my god!" said one family member.
An aunt said, "What? It's a boy! Are you kidding?"
Grandma's reaction was priceless. She found out when she went to change the baby's diaper and exclaimed, "Oh my God! You've got to be s----ing me!
Dr. Lisa Masterson says getting the baby's sex wrong is more common than you'd think when sonograms are involved.
Dr. Masterson told INSIDE EDITION, "There are multiple things that factor into the accuracy of the ultrasound. The fluid that's around the baby, because there's less fluid then everything is kind of squished up and you can't delineate all the borders. The position of the baby. If the legs are crossed and you can't really see if there's a penis or not."
So, for this family, it's a time of joy. A beautiful new boy has entered the world, even though she turned out to be a he.