"I thought it was important that you be the first to know", she told fans in the video.
Janet was seen shopping for baby items in London last month, showing off what appeared to be a bump beneath her casual outfit.
Do you think Janet is at risk of losing her baby? She's doing great. Janet feels really strong and is just so excited for the baby to come. She didn't confirm or deny the pregnancy, probably to protect her privacy and because pregnancies are always tricky in the first stages. But I have not forgotten about you. "It hasn't been the easiest pregnancy at all. She is a very special and talented woman who never ceases to amaze me".
We all knew the singer, part of the famous Jackson clan, was having a baby.
Clinton proposes tax relief for families with young kids
On a static basis, taxpayers in the top fifth of income would receive tax increases and everyone else would receive tax cuts. But even that analysis found it would leave a net deficit and that more of its benefits would accrue to wealthier taxpayers.
Jackson continued: "We're in the second leg of the tour and there has actually been a sudden change".
It will be the first child for Jackson, who is married to Wissam Al Mana.
Australia's Sonia Kruger had a baby at 50 but openly admitted she used donor eggs.
Could Jackson and husband Wissam Al Mana be expecting their first child? Sources and even big brother Tito Jackson talked to press about her being pregnant, and there were even rumors about her being on bed rest.
Dismissing reports that they were planning an "extravagant wedding", Janet revealed: "Last year we were married in a quiet, private and lovely ceremony".