Read this: In August, the couple attended the 2011 MTV Video Music Awards, at which Beyoncé performed "Love on Top" and started the performance saying "Tonight I want you to stand up on your feet, I want you to feel the love that's growing inside of me". At the end of the performance, she dropped her microphone, unbuttoned her blazer and rubbed her stomach, confirming her pregnancy she had alluded to earlier in the evening. Her appearance helped that year's MTV Video Music Awards become the most-watched broadcast in MTV history, pulling in 12.4 million viewers; the announcement was listed in Guinness World Records for "most tweets per second recorded for a single event" on Twitter, receiving 8,868 tweets per second and "Beyonce pregnant" was the most Googled term the week of August 29, 2011.

What song did Beyoncé sing prior to announcing her pregnancy?
What is the answer? (If it cannot be answered, return "unanswerable")
Love on Top