I Was Prescribed Prednisone (10mg, 6 Day Pack Of 21

I was prescribed Prednisone (10mg, 6 day pack of 21 pills) for a case of contact dermatitis. I am on the fourth day with four pills remaining. I noticed last night that I was experiencing some shortness of breath after taking my last pill of the day, and I have had the same issue with both of today's doses as well. It's not enough that I feel unable to breathe, but it is noticeable. My doctor is unable to take my call. Is this a side effect that should cause me alarm, or is it common?