You fall into a more common category than you might realize of women who complain of lack of breast development. Though your breasts have probably stopped growing at age 18 I have met the rare person who tells me that her breast began development between the ages of 20 and 22. I would not take birth control pills solely to enlarge your breasts since the effect may be modest at best.
I would generally suggest to my patients that they wait until they are closer to 20 before considering placement of breast implants but this is a personal decision.Warm regards,
Jon A Perlman M.D., FACS
Diplomate, American Board of Plastic Surgery
Member, American Society for Aesthetic Plastic Surgery (ASAPS)
Beverly Hills, California
Other than the changes of weight gain or pregnancy, I suspect your breast development has stopped. Birth control medications do sometimes make the breasts a little fuller while on the medication.