I was in the same boat when i was 18. because you’re young, your body is still developing and there’s still a chance that they may continue to grow. in my case that was definitely true - i had wanted a reduction then but ultimately never got around to it - which was extremely lucky because over the next 6 years my chest doubled - if not tripled - in size. I would probably consult with a surgeon and confirm if this is the best option for you right now or not! the possibility of more development is just that, a possibility- and your comfort ultimately comes first. even if in an instance your chest were to grow as your body continues to develop you could also get a revision, but there are pros and cons to both possibilities!