Some of my trees are shedding old leaves, but nothing major.

I think it may be caused from a change in environment. Two days shouldn't make a big difference, but you never know. Have the temps or the amount of light changed dramatically when inside?

My citrus are not dropping leaves yet as we are still in the 90's here in GA. Next week the temps are supposed to change but I don't know to what extent at the moment.

Probably due to significant changes in light conditions and temperature/humidity. Try not to stress too much; it is a common condition seen in Spring and Fall when you move them in/out.

Ok I feel a bit better now