cortisone shot 12 weeks post-surgery?

I had biceps tenodesis and subacromial decompression surgery on my left shoulder 11 weeks ago (2/26/2007). I started my stretching exercises the day after surgery (as prescibed) and have been stretching religiously twice a day for at least an hour ... PT two to three times a week ... 3 advil before I stretch because there's a lot of inflammation ... I use lots of ice ... I haven't been in the pool yet to kick because the thought of a bathing suit strap on my shoulder makes me cringe... My passive range of motion numbers are: flexion 140°, abduction 105°, IR (at 90°) 20°, ER (at 90°) 40°, IR (at 45°) 40°, ER (at 45°) 35°. Because of the inflammation and because my PROM numbers aren't where they should at this point, my PT and my OS want me to have a cortisone shot. Has anyone had an issue with inflammation this long after surgery? Has anyone had a cortisone shot this soon after surgery? Are my PT and OS being impatient? Am I screwing up my recovery by not having the shot? I had a cortisone shot two years ago, which worked like a charm for 18 months. My second shot was 8 weeks pre-surgery and was not effective. This will be my third.