cadillac - i think you did the right thing. when my oldest son was in a centre daycare years ago the 'no interuptions during naptime' rule was not flexible and i follow the same policy here.
as a parent i would be very upset if my child didn't get the benefit of his/her full nap because another parent thought their plans more important.
obviously some exceptions apply, but in general, a trip to a cottage can be delayed by thirty minutes.
ps i am almost three months pregnant too and can't wait for the first trimester to be over. i'm so exhausted! i was very, very sick for a few days so i have started taking diclectin which has a side effect of drowsiness so i think i'm getting it two-fold. also, my patience are totally shot... i have a very short fuse these days. when are you telling your clients?