first of all congrats Wendy on your surgery! I hope it all went well. I actually lost quite a bit of weight while in the hospital. The last weight I have gained over the past few months has all gone to my breasts and backside, so I think it's natural to lose a little breast size just because of that, andthe fact that all your energy is now going towards healing more than growing breasts. I was off my E just under 4 weeks altogether. Since my surgery I have been really eating a lot of high protein foods and drinks, and after being back on hormones just a week I seem to be experiencing a little breast growth, especially now that there is nothing to prevent it.
Also remember that hormones are a long term thing, so being off for a few weeks is not going to make a great difference. Some of it may be psychological too- I know going off just for that short time really did a number on my head.
Anyways, I'm sure you'll be fine- just give it a bit of time