Good Morning America received a surprise caller as Oprah Winfrey was the special guest for the Thursday morning show.

Robin Roberts called in during the show to update her viewers on her recovery from her bone-marrow transplant last month.

"It's day 35," the 51-year-old TV host said, referring to her procedure in her battle with Myelodysplastic Syndrome (MDS). MDS is a blood and bone marrow disorder.

"Thirty-five days ago, I had my bone marrow transplant. It is a journey."

Robin added that she is "incredibly blessed" to recovery as fast as she is.

"Some days I do feel like I am 35 days old and can't get my head off the pillow, but those days are becoming fewer and fewer."

"It would be a lot easier not to be so public when you're going through something like this... it's a privilege to be a messenger," Roberts said.

Roberts shared with Oprah, who was a bit teary-eyed during the different segments of the show, that she's been carefully documenting her journey back.

"I'm journaling- -you'd be very proud of me, Oprah. Journaling a lot," Roberts mentioned. "And just so appreciative of the outpouring. Not just for me but for everyone."

Oprah told Roberts that she felt her presence when she walked into the studio.

"I am so happy to be here with your family ... you are here in spirit and we are so happy to have you call in this morning," Oprah said.

Roberts replied and said "can't wait to come back."

"I want to come back on that couch with those froggy slippers," Roberts added. "It's just about understanding the moment. Why I am here now."

Roberts took her medical leave from the highly watched TV show in August to prepare herself for the surgery on September 20. Robert's sister, Ann, was her donor.

The ABC anchor beat breast cancer five years ago, prior to her current medical condition.

Tags: Robin Roberts Oprah Good Morning America GMA