I am 27 weeks pregnant and I was wondering when about is the normal time for a baby to turn?

It can vary. Before 36 weeks the baby can change positions quite a bit. After 36 weeks more babies will be found in the head down position but some still change after that time. If your baby isn't head down and you are close to your due date your doctor should discuss this with you.
Highly variable. And dependent upon baby and mother's sizes, position in which baby is located. And variety of other factors. May not happen. You might discuss this with the obstetrician on your next visit. Have a great baby. Good luck and best wishes.