Yoga for Osteoarthritis

Hi, I took up Yoga just after Christmas and am loving it. However I am currently waiting to see a consultant to see if I can have a Hip Replacement. My Yoga teacher has given me a list of exercises to do, but as I am in a lot of pain, I am a bit scared to do them on a daily basis.
Has anybody else experienced this? Should I grit my teeth and go through the pain barrier?