Fill in the blank: The _______, they are a'changin'

If you guessed boobs, you're right! For the last week or so, my boobs have been growing. The right more than the left, to add to the oddity. I have always been not-quite an A cup, not being able to actually fill the cups. The result is that I don't even own a bra, because really? what's the point? Now I think the right one has moved passed A and is making a run for B. The less ambitious left (or perhaps this is a turtle and hare type event?) is plodding along behind. I'm starting to feel like I could use a bra, but how do I know what size? What if they keep going and I end up looking like one of those women who didn't know you could choose any size of implant and now looks like she'll fall over at any minute?