She didn’t seem worried by the slip up, tweeting: ‘Accidental announcement tonight on @jimmykimmel’.

The 32-year-old looked elegant in a little black dress from her new maternity line, paired with fuchsia pink high heels and a glamorous half updo.

But her most striking accessory was her large baby bump. Jessica fell pregnant with her second child when her daughter Maxwell was less than a year old.

The pop star and her fiancé Eric Johnson confirmed they were expecting their second baby back in December.

Jimmy asked what Jessica’s father Joe Simpson, who is an ordained minister, said when his daughter got pregnant out of wedlock.

Jessica said when she told him she was pregnant the first time, he said ‘Well what are we going to do?’ And the second time she fell pregnant, Joe was more resigned, merely stating, ‘Oh honey.’

When asked whether she and Eric plan on having more kids, Jessica stated:

‘I really don’t want to be pregnant again because this pregnancy is really rocking my world right now.’

Jimmy also mentioned Jessica’s best friend Cacee Cobb, who is pregnant and due around the same time as Jessica.

When asked if the two had planned it, Jessica replied, ‘Well it’s definitely something we would love to have happened. We want our babies to be best friends, ’cause we are.

‘So now we’re going to force them to go to school together, force them to eat sandwiches together.’