Stress Fractures from Swimming?

Hello all, I was wondering if anyone has heard of getting stress fractures from swimming. I have rheumatoid arthritis, but have never had a problem with fractures. About 8 months ago I really started having problems with the muscles in my back/shoulder (in the lat/trap area) and thought it was from increasing my workout yardage and intensity. Then I had a nasty tear in my lat and only did kick workouts for 6 weeks. Now, I'm full steam ahead, have picked up my yardage on one workout a week, and looking forward to meet season in a month. Well, the doc tells me today that I have swelling in my left collarbone area (same shoulder that was injured) and my upper thoraic verterbrae are SUPER SENSITIVE!!! He has ordered X-rays, but I'm worried. I mainly do IM workouts with all sorts of drills, etc. for all of the strokes. Is it possible to fracture vertebrae between your shoulder blades from too much fly? I REALLY don't want to miss comp season, as it will be my first one back in 9 years and am super stoked! :badday: