Um, one month on HRT?
So your left breast is about a D cup while your right breast is about a B cup?
Whoa! Slow down! Breasts take a while to develop. They don't grow at the same pace.
Most natal women have some asymmetry to their breasts.
I believe that in most cases that the left breast is larger.
So, give your breasts another few days and see if they even out.
Oops, I meant another year or two.