Being a 32A since puberty is absolutely normal. Breasts come in all shapes and sizes. Breasts can also change as you get older and gain weight over your lifetime. If you are interested in larger breasts, seek a consultation with a board-certified, by the American Board of Plastic Surgery, plastic surgeon to discuss your options.
and yours falls into that range. As mentioned by others, breasts change with life changes. Luckily for women who desire larger breasts, implant surgery is safe and predictable and something you could consider if you wished to do that.