pbr Rod Stewart's enormous clan is getting even bigger. The singer has confirmed that he and wife Penny Lancaster are expecting another child.br ppbr The couple, who have a four-year-old named Alastair, said: "We were thrilled and delighted to be able to tell Alastair that he was going to be the big brother to a little baby."br ppbr Their newest addition will arrive in mid-March, just after Rod's 66th birthday and just before Penny celebrates her 40th.br ppbr The model apparently discovered she was pregnant while they were marking their third anniversary recently in Italy.br ppbr Rocker Rod has five children from previous relationships with Alana Hamilton, Kelly Emberg and Rachel Hunter.