oh, grim news 
Especially after the 'midwife sonographer' at the 12 week scan told me it was posterior.
The OB said decisions would be made at the 20 week scan, but there's apparently a very high risk of adhesion to my previous CS scar, and thus risk of haemorrahge during this CS. Thank God she isn't recommending a VBAC though 
Anyone else had this?