There are very few things that can reliably increase your breast size. The creams don't work. Exercises can sort of increase the size of your pecks (the muscle under the breast), but breast tissue is made of fat and the glands and ducts that produce milk--not muscle.

For some women, birth control pills do increase the breast size, but not for everyone and it depends on the type. The estrogen and progesterone in birth control pills could advance breast tissue growth and or fluid retention, making your breasts fuller and larger, but they may also become a bit tender to the touch. The larger dosage pills are more likely to increase your breast size, but they are also more likely to give you side-effects. Talk to your doctor about this.

Gaining weight can increase their size--again, they are made of fat, so when you increase your body fat, it goes everywhere, including your breasts. Unfortunately, when you lose the weight, they go right back down.

Also, your breasts may be done growing, but they may still fill out. Mine filled out quite a bit between 22 and 26 (I was kind of amazed).

Listen, your fiance loves you, right? If he didn't want to be with you, the way you are right now, he wouldn't be marrying you. Is his body 100% perfect? I would bet not. No one's is. You are building a life together, it's not all about your breasts. Maybe he's a butt man. Or leg. Or maybe he loves you for who you are. Ever think of that? If he has made comments about how small you are, then that's not right and you should really think long and hard about whether that kind of attitude is something you can deal with. If he hasn't, then don't worry about it so much. Okay?