The 37-year-old singer is expecting her first baby with husband Josh Duhamel and isn't denying herself any of her favourite foods, reported Us Weekly.
"She is eating everything safe and not prohibiting herself. She is ecstatic to be pregnant," said a source.
The couple are so excited about the baby, they are already planning the nursery.
"They will start decorating the nursery soon. Josh is good with kids because he's such a big kid himself," the insider added.
The 40-year-old actor recently revealed he is looking forward to "imparting life experience" on his child.