Bra Size Questions

I’m going to start off by saying I am completely confused by bra sizes and can’t figure it out.

My band size is a 32.

I was previously wearing 32A before I realized it was too small.

While comparing 32A and 32B they seem pretty much the same size in the cup area,maybe a little tiny bit bigger.

34B,the cup size seems to fit better and is bigger in the cup than 32B BUT the band size is too big.

I measured myself but still can’t figure it out.

Band Size- 28 in

Bust Size- 31 in

In conclusion....

32A- cup size too small/band size fits

32B- About same size as 32A so doesn’t fit in cup area

34B- Cup size fits better/Band size too big

Can anyone help me?