Hi there.
The human body is normally asymmetrical, and at age 21, I believe your breasts are still continuously developing and has still to attain final adult size.
However, given your previous surgery and fibroadenoma history, it will be prudent to have this evaluated with imaging studies such as mammogram or ultrasound to see if there are new changes pointing to your previous condition.
I would suggest you discuss this option with your doctor and have your breasts evaluated just be sure. All in all, I believe this is nothing to get worried about.
Regards and God bless.
Detailed answer for your question: Available in paid version. - Click to pay.
Second opinion from another doctor: Available in paid version. - Click to pay.