Don’t worry about it. Everyone is different and it’s to do with genetics too. One of my friends was like you growing up as myself and others had bigger boobs than her but honestly we all wish we had the size she has.
But think on the plus side, you’ll find prettier underwear and bralettes and outfits (potentially) than the bustier girls!
Girl dont worry about it at all.. It is simply genes and sometimes its just they grow faster than you do love.
Some chest exercise and food habits can make your chest grow!
I'm sorry if it makes you sad, sweetheart. They will come, there is no hormonal treatment you need. You will probably wind up a cup size bigger than your mom, if my experience serves as an example.
And in case it helps, please keep in mind that the bigger the breasts get, the fatter the woman looks overall. Women who look lovely and slim are most often women with not-huge boobs.
Up to my pregnancy, I was a 34 band and sometimes an A cup, at most a B (depending on the bra). While I was a bit annoyed about not being buxom, I did like being slim and sleek. I didn't realize how much it was associated with the boobs, until after I had my child and gained a good cup size in the breast. My pants remained the same size, so my hips and waist didn't expand, but suddenly just from the fact that I had boobs, I looked almost matronly, with a prow-of-the-Queen-Mary look that was not particularly flattering or youthful. So, be careful what you wish for, you might get a look you don't like. Not saying you don't want boobs! but just take joy in your loveliness right now, exactly as you are, and always.