11 week old hasn't pooped in 7 days

Katrina

My little man is 11 weeks old today and hasn't pooped in 7 days. He was getting formula top ups until 7 weeks old and has since been ebf. Since dropping formula his poops evened out to once a day, but this past week nothing! It's odd for him, I know it's usual for BF babies to go a week or 2 but it's unusual for him. Any advice to help get things moving? He doesn't seem unhappy and farts all day long. Tia x