baby head low and measuring bigger

I just had my 31 week check up with my midwife and baby's head is very low according to her. She said I need to sit on my birthing ball (not bounce) and not to slouch as it can push baby's head further down. she also said My bump
Is measuring slightly bigger than average. She said we will review it on my Next appointment. What can this mean for Me and my baby? Head low and measuring bigger? Thank you 🙂xxx