Im 37 weeks and just found out my baby is breech...?

Im 37 weeks pregnant, My doctor sent me for an ultra sound because my belly is measuring 40 weeks. They have been telling me that the baby is head down for the past month. Needless to say i went to have the ultra sound yesterday and the first thing they said is ur baby's head is under ur right rib and is measuring 39 weeks and 4 days. The lady giving the ultra sound said it is most likely that he wont turn on his own because of his size and having no room to really turn. I was wondering if anyone thinks it might still be possible for him to turn still... and If not, would a c-section be needed ? ? ? ?