Unfortunately, not all women have large breasts. If you are worried about breast feeding/nursing a child down the road, they grow for that! Otherwise, learning to love your body is important. Many men are attracted to women with smaller bust size. Don't let society make you think you need big breasts. You don't. Overall, they will change throughout time by growing with pregnancy, growing when you age, shrinking when you are done nursing, shrinking when you lose weight, grow, shrink. That's what breasts do. You can try to do some pectoral/chest exercises like lifting weights doing chest presses or push ups and that grows the muscle under which push outs the breast tissue. It may enhance them a little.
Surgery has a lot of issues including pain, cost, an outward sign of something unnatural about you as men can spot boob jobs a mile away, replacement every 10 to 15 years for life, etc. But they are a quick fix in general.
good luck
First off, they will probably grow, it will just take more time than you think you can stand to wait. But I would not mangle my body with surgery in my impatience, if I were you.
Second of all, men are attracted to women who think they are hot stuff. It DOES NOT MATTER if the woman is fat, thin, long-haired, short-haired, black, white, purple or pink -- confidence and joy in yourself is a magnet to men. As specialmom says, learning to love your body is important. Just like guys who are all freaked out because their penis is not as huge as a porn star's, focusing on one body attribute and imagining it makes one unattractive, is a really counterproductive thing to do. (In the man's case, huge penises are not attractive to women anyway, so here he is beating himself up over something that doesn't matter and also making himself less attractive by being so underconfident.)
Do whatever makes you happy. Find and follow your passion. You will attract men no matter what the size of your bra cup. You are SO MUCH MORE than shape, and besides, slender women are super lovely anyway.