The couple - who already have 22-month-old son Axl Jack together - are believed to be considering going down the adoption route for their second child.
A source told US' OK! magazine: ''They think it's the right time to expand their family.''
Meanwhile, an insider previously claimed that Fergie's ''obsession'' with the gym was halting any plans for her and Josh to have a baby.
They said at the time: ''Another baby just doesn't fit in with Fergie's life at the moment [even though Josh is] desperate to have another kid.''
Josh has made no secret of the fact he wants a brother or sister for little Axl.
He said: ''We've got to be very strategic in our planning for it. But the plan was to always have at least two.
''It's still crazy to think that kid is mine and that we made him. It's like, 'Holy (expletive)! We made him!'''
And whilst the 42-year-old actor would be happy having either a daughter or a son, he is secretly wishing for a boy as he admitted growing up with three sisters taught him girls could be tricky as teenagers.
He said: ''[My sisters] taught me that I would be really happy to have another son.
''Girls are great. I would be totally happy to have a girl, but ... they get to be those teenage years and [want] independence, you know? It isn't always easy - especially for the mother.''
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