Mine were 38f before my first pregnancy and went up to a 42kk while breastfeeding. Then they went down to a 38I.
Then I had breast reduction surgery. I was a 38C and went up to a 40DD during and after pregnancy. Now they are a 40D a year later. It's different for everyone. Usually if you were smaller before, they will shrink back down. There isn't anything you can do about it.
My band size hasnt gone up but my cup size has gone from a DD to bigger than an F. I'm not sure what size I'm actually in since motherhood maternity only went up to F and it did NOT fit lol. I'm rocking the padded sports bra until I can order one lol.
I'm 36 weeks and mine have only increased and I increased a cup size. I've only gone from a 32a to a 34b. I've been told not to look forward to keeping them because even after breastfeeding, they could still go back to their original size...or worse, shrink up even smaller...lol That would not be too good for me. :/