Erm....most likely you are not done growing. It isn't abnormal for guys to continue to grow until the age of 18 or 19, or so I've read in several places. Seems to be the case too, as I have grown a bit even though I thought I had peaked out at around 17 (I'm currently 19).
You seem to have one growth spurt in your early/mid teens, then you level off for awhile. Then you can actually grow a bit more. Of course, everyone's different, so I'm just speaking in generalities here.
Some people say that it's bad to do lots of strenuous weightlifting before you're finished growing as your bones are still moving around and it can do permanent damage, stunt growth, etc.
Don't know what I really believe myself, but I have always erred on the side of caution and never did much heavy stuff just in case there was some truth to it.
Of course, doing major heavy lifting at any age can be dangerous if you're not prepared for it. Build up your weight slowly, no need to rush.
That's my philosophy anyway....
Just my 2 wooden nickels.....