Uhm, if it can comfort you any, at 10 months, I have nothing. What? Having a crappy dose makes me not count? Okay~
But wait. What are you sad about? 7 months and an A, that's... A lot, really. Especially considering that you're relatively thin.
My best friend, at a bit over a year of HRT, is still growing. She thought they had stopped at her halfway-between-A's-and-B's, but then they had a growth sput a month ago, and it's still going on. She thinks she might get full C cups with a little bit of luck. So...
Wait. As far as I know, the average woman has small B's. Of course, on a trans woman whose ribcage is unfortunately too big, you need more to look the same, but still. Even on a trans woman, B's look acceptable. And from the looks of things, that's probably what you'll get, at least.
But whatever you want to do, I think you should wait until you've had 2 years of HRT. That's when most growth should have settled down. They say 3 years, but since you're an impatient person and the last year doesn't have a massive lot of changes, I think 2 years is wise enough.