The size of underwear should be divided into bust and cup. For example, 70 is the bust and B is the cup. Do you think small means small and tight chest circumference or small cups, which feel like cups are pressed up? It is also related to the shape of the cup. If you think B75 is a little big, it may be that the bust is appropriate, but the cup is a little big. In this case, you can try to buy 1/3 cups or 1/2 cups, which may be better. Some brands of underwear will have the size of+cups. You can try. Maybe A+ suits you better.