I have been having similar pains except at first, they were constant and in both legs and felt like extreme shocks or charley horses, some of the worst pain I have ever experienced besides child birth. Turns out calf pain is a side effect that is listed as a that you should call your doctor if you are experiencing. We are not the only ones.
It was hard to find anything that listed calf pain as a side effect, but here is one and it says contact your doctor if you experience calf pain.
Defintely tell your doctor before your next infusion, ok? The only other thing I could think of is that you are tapering off the Prednisone and that can cause pains. But if they only started after the last infusion, I would think it's the Remicade. Tell us what he says about it please.