Hannah, The short answer is no. It could be done, but there are many concerns to be addressed. Issues such as have your breasts finished developing, why do you want this surgery, do you have the prerequisite maturity for this surgery, and how is your overall health. The only way of addressing these issues is to have a consultation with an experienced, Board Certified Plastic Surgeon, to discuss your options.
Thank you for your question. It is relatively common for 18 or 19 year olds to get breast augmentation performed so you are not too young. I would caution you though on how large you wish to go. At your age I would stick with a conservative (smaller size) so that over time and with aging you don't stretch your skin out too much with large implants. Best of luck to you