Britain's Prince William And His Wife Catherine, The Duchess Of Cambridge, Arrive With Their Son Prince George At Sydney Airport April 16, 2014.
Britain's Prince William and his wife Catherine, the Duchess of Cambridge, arrive with their son Prince George at Sydney Airport April 16, 2014. Britain's Prince William, his wife Kate and their son Prince George flew from New Zealand to Australia, where they will now spend nine days touring the country. Reuters/Phil Noble Reuters

Kate Middleton is reportedly past her first trimester in her second pregnancy yet the gender of her baby is still unknown. Additionally, it's still uncertain if the Duchess of Cambridge will have twins this time. However, according to a recent report it's likely she and Prince William will welcome two new royal babies in April 2015.

According to Woman's Day, there are two reasons why Kate Middleton is set to give birth to twins. The Australian publication quoted a source who told Star Magazine that the Duchess of Cambridge knows she is carrying twins. Her recent ultrasound reportedly revealed two royal babies.

"When they looked at the screen and saw two tiny human beings, they were completely overwhelmed," the source who is reportedly close to the royal couple told the US publication.

Kate Middleton was reportedly surprised at what she saw. According to the source, Kate's reaction at seeing the ultrasound "must have been priceless." Prince William supposedly even recalled how the Duchess reacted to the images. The source claimed William saw the Duchess' "mouth dropped open and her eyes almost popped out of her head, then she squealed, 'Oh my God!'"

Additionally, betting odds over Kate Middleton's second pregnancy reportedly also hinted at her having twins. It's supposedly surprising why wagers on whether Kate Middleton was carrying twins were suddenly suspended across a number of British betting agencies. According to Woman's day the suspension was announced after a frenzy of punters started betting their money on the Duchess carrying twins.

"We've had a load of unexpected bets including a large number of new accounts -- with any other market I would say people know something," Rupert Adam, spokesman for betting agency William Hill, said.

If Kate Middleton is indeed carrying twins then it would be welcome news for the royal couple. The Duchess of Cambridge reportedly wants a larger family and wants at least three children.

However, Mirror UK contests that Kate Middleton couldn't be carrying twins. The palace's announcement on Kate's due date reportedly only confirmed she is pregnant with "a baby" and not babies. Regardless, the palace would have to officially confirm any details on the Duchess of Cambridge's second pregnancy.