Baby flipping? Breech or not?!

Sophie
I had a scan at 20 weeks where baby was breech, then I saw midwife at 24 weeks who said she was head down as she could feel it... Then at 30 weeks I had a scan at the hospital who said she was breech, but the next day I had a 4d scan who said she was head down?! 
Can she possibly turn that often? Or has someone got it wrong?! 
Xx