Due date wrong or big baby?

I’ve just been for my 34 week midwife appointment. She measured fundal height and has said he’s grown 4cm in the past two weeks so now he’s showing as a large baby therefor I need to go for a scan. I’m just wondering if they’ve actually got my due date wrong as when I first had my booking appointment she told me my due date was the 29/05/2024 but when I went for my first scan they told me my due date was 23/06/2024 so it jumped a month. Im just wondering if I’m actually due somewhere in between? Has anyone else has a wrong due date or a baby that’s larger that they should be? I’m trying not to worry or work myself up but it’s a little frightening as this is my first. Everything’s been perfect and I’ve had such an easy pregnancy up until today