The Saturdays singer Rochelle Humes says keeping her pregnancy a secret was hard.

The 23-year-old star is expecting her first child with her husband, Marvin Humes of JLS, admits she found it difficult to keep her joyous news a secret from her bandmates - Una Healy, Mollie King, Frankie Sandford and Vanessa White - because they know her so well.

She explained to new! magazine: ''Being pregnant is the hardest secret to keep anyway because you have to wait for the safe point it was definitely strange. The girls were saying, 'Let's go out for sushi', and I'm the biggest leader for that usually. I'd go quiet and disappear into my room.''

Sushi - a Japanese raw fish delicacy - is considered unsafe for expectant mothers, and the rest of the group quickly grew suspicious of her.

Mollie, 25, said: ''We know each other so well. After a while, we were like, 'You're not eating sushi, what's going on?' ''

Rochelle added: ''They all had 'the chat' without me and said, 'Are you pregnant?' ''

Although Rochelle wasn't able to hide the news from her fellow 'Ego' hitmakers, Vanessa concedes: ''It's hard enough to keep a secret from us anyway.''

The five girls can soon be seen in E! reality show 'Chasing The Saturdays' which follows their efforts to crack America.