So four years ago, I was told that I couldn't have children, and it's OK, I'm going to have children, trust me. When the doctor told me, my reaction was, 'Oh hell nooooooo,'" she told the crowd.
"I wanted to write this song for myself in my moment of pain and of sadness. But, also to give myself joy and give other people something that they can listen to in that moment when it gets really hard."
Channing – who announced his split from wife of nine years Jenna Dewan – was also in the audience and took to social media to share his admiration for Jessie.
"This woman just poured her heart out on stage at the Royal Albert Hall. Whoever was there got to witness something special. Wow," he wrote.
Jessie also took to social media to share her love and thanks for the outpouring of support from fans since her announcement.
"The love and support I have received has been overwhelming. Thank you," she typed in her Instagram story. "I was told 4 years ago I won't be able to have children. I was also told I would need a hysterectomy immediately and to be put on medication." Jessie J revealed she "refused" the procedure.
"I'm off all medication through natural medicine and diet change," she continued. "I haven't given up hope. I am doing all I can to make it happen the best way my body will allow."
My journey is just one in millions that exist," she wrote. "I stand with you ladies. Strong in our emotional pain. To turn it into joy."
She continued, "I will be a mother. As will you. I believe in miracles. But if it doesn't happen naturally. Then that wasn't meant to be the journey. But a mother is within all of us. That inspires everyday. We are strong! Time will tell."
Jessie also recently opened up about the comparisons that she bears a resemblance to Channing’s ex, Jenna.
"I rarely, but sometimes see that my name is involved in stories online that I do not agree to. I often ignore them as 99% of the time it is something that doesn't serve any positivity to speak on," she penned. "However there is a story I have seen be re written over and over again in the past few weeks that talks about myself being compared directly to another beautiful woman regarding our looks and people picking who they think is prettier."
It's constant with women. Picking favourites. Do the media do it with men? No. Are women gaining a positive lesson from it? No. You only have to look at a few of the comments to see that these stories are not inspiring women but mostly women ripping other women down," she continued.
Jenna also took to social media to praise Jessie.
Amen Jessie! Yes!!!!! Women for women all the way. No need for negativity. Let's live in a world where we support each other and raise each other up," she wrote. "Like i said before, positive vibes all the way. Nothing but respect."