my first was born breach by c/section - that decision was made at 38.5 weeks but not in light and was after positioning exercises, attempts at turning and viewing position and on review post birth it was the right decision at the time ( alot of post birth factors regarding positioning, size, skull fusion etc to be considered in this instance). I could have given it a bit longer if I had liked but due to knowledge at the time went with the c/section.

my other two however flipped up and down all the way up to 37 weeks before they positioned themselves head down and remained there - they were both dramatically smaller than my first and still had plenty of room to move and were much more mobile throughout the pregnancy anyway

some babies don't turn until just before labour I believe so as late as the 39/40 week mark. Some OBs might look to apply pressure early but none of mine have considered it an issue prior to 38 weeks other than to comment on if they don't turn prior to labour we will have to discuss c/sect (due to their position on delivering breech babies) and by 38 weeks my other two have all been head and ready to go - pity other issues then got in the way for VBAC.

I wouldn't be worrying about it yet and would be working on the exercises as you are.

A friend of mine just had her third and she was still flipfloping until 37 plus weeks - baby turned and she had VB in 1.5hrs at 39 weeks.