My baby was breech around 35 weeks also. Do you know how much amniotic fluid you have- on the high side or low? The baby doesnt have much room, but its still possible for baby to move. Im 37 weeks and my baby is now head down. You can also try going on all fours (knees and hands) so baby can have more room to move. I hope a little miricle happens and your baby will turn. You still have some time.
I honestly would let them try to turn the baby. There are also exercises you can do at home to coax him/her to turn. Ask your doctor about that. But if his heart rate goes too low then they would just give you your c-section. But having a vaginal birth is much better than a c-section. You will heal quicker and feel normal within days.