I worked really hard to increase my supply with Charlie, and I never saw it drop in the 9 months I pumped. I also never got my period the entire time.
With Olive, I have a small stash because I'm really only pumping enough for her daily bottle feedings and nurse at night, so I haven't frozen anything in a long time. I'm concerned that I should be building up more of a stash so I can be away from her more in the future, esp if my supply starts to decline at some point.
Did you see you milk supply decline at some point while breastfeeding/pumping?