Wow, Stage 4 already? Are you sure? I thought it took a LOT longer than that to reach that point. Although don't worry too much; like you've already realized, a good number of the women here are already fully-developed and still manage to grow. Also keep in mind if you're wearing a larger band, reaching an A cup will take longer, as it is a bigger size than say an A-cup girl wearing a 30 band. I started as a 34A 1/2, and that wasn't too small. I'm not sure what band you're wearing, but it's gotta be around that. Don't get too hung up on cup sizes.

If you reach Stage 5 before I do, I'm going to be so mad!