"They are expecting her to give birth early," the source says, noting that the couple are currently residing at their home in Sonning, England.
ET has reached out to George's rep in regard to Amal's due date.
The two have been keeping a low profile in recent months. On April 26, George showed up solo to a red carpet appearance in London, while Amal's last public appearance was at The Promise premiere in London on April 6. The couple were also spotted taking a stroll through the Berkshire countryside on April 2.