Beyonce, Blue Ivy Carter Together Onstage, Baby Bump Showing? [VIDEO/PHOTOS]: Adorable Baby Blue Joins Mom for 'Irreplaceable,' Pregnant Rumors Swirl

Queen Bey fans in London got an awesome onstage surprise during a Mrs. Carter Show performance on Saturday evening (May 4). While singing her mega-hit "Irreplaceable," Beyonce had adorable one-year-old daughter "baby" Blue Ivy Carter join her up onstage for the finale. Dressed in a cute white dress and donning a pair of protective headphones, little Blue Ivy pranced around the stage while Mamma B busted out the last few notes of the tune. For a quick second it looks like Beyonce's ready to hand the mic over to baby Blue, but the youngster steps to the side to let the Queen finish off her performance. Check out the fan-shot video below! Meanwhile, several fans insist that Bey's definitely starting to show signs of a slight baby bump... is Jay-Z's wife preggo again?

UPDATE: Beyonce Baby Bump Spotted at Met Gala 2013? PHOTOS: Pregnant Rumors Swirl with Sexy Dress, Bulky Belt Ensemble, Queen Bey Admits Blue Ivy 'Needs Company'

Check out Beyonce's stellar (and sparkly) performance of "Irreplaceable" at the O2 Arena in London on Saturday. Baby Blue joins her onstage at around the 5:40-minute mark:

The clip soon went viral, already garnering over 26,200 views.

One Mrs. Carter fan posted this adorable pic on Instagram:

bonang_m: "This moment!!! #mrscarterworldtour."

Beyonce recently admitted that she definitely wants to have more kids soon because Blue Ivy "needs the company" (read more on that here). After flaunting that bright, sparkly jumpsuit at her London performance, rumors started swirling online that Beyonce's second pregnancy was "definitely beginning to show." Do fans agree?

As one fan simply puts it:

ledjin: "I see a baby bump!"

Will baby Blue get a sibling to play with sooner rather than later?