Tennis star was pregnant when she won Australian Open in January 2017

Tennis star Serena Williams have announced that she is 20 weeks pregnant.

Serena who got engaged to Reddit co-founder announced on her Snapchat that she is pregnant.

That means that the tennis champ was pregnant when she beat her sister Venus Williams to win the Australian Open on Saturday, January 28.

The 23 Grand Slam winner was nine months pregnant when she beat her sister 6-4, 6-4 to win the Australian Open.

Serena announced in December 2015 that she is engaged to Ohanian although they did not reveal a wedding date.

The pregnancy announcement comes just a day after Serena shared a photo of her being carried by Ohanian in a cute photo

"My only regret is not pointing my toe! Sorry coach Garry," she wrote alongside the photo.