Hi Angela,
I also agree that you are responding fast and looking nice
Congrats!
Regarding the cups.
I've been using the mediums since I started NB back in November last year, and I still see progress
I'm going to keep at it until I really can't put them on at all, because they won't fit inside
There were times I tried the larger domes though( I have them all, L, CL and XL, besides the XL I tried them all), and I agree with what melissa4u and Not so teeny tiny were discussing in a topic about this subject, that the medium domes seem to give more outward growth, while the larger domes give more fullness, a rounder shape, since it pulls more on the sides, and growth in width.
You can see on my pictures that my breasts extend outward from my ribcage quite a lot, and while they have started rounding out and developing more side boob, the outward growth is what's really noticeable. I think both have its advantages, since with the outward growth, you seem to grow measurement wise, and in your tops, the breast sticks out further, but the downside is that its doesn't look that big, and full. While with the side/width growth its the opposite effect, you might not see a change in measurements, but feel and also look much bigger.
Anyhow, congrats again, looking forward to seeing your progress.
Take care