Here is my 2 cents worth....
I had it done in 1996 at age 26. I had saline implants because they didn't use silicone at that time. I went from an A to C, placed under the chest wall muscle. I had it done on a Thursday, recuperated over the weekend and went back to work Monday. It did hurt like heck, especially the first 2 days. The pain meds were a lifesaver. The first 2 nights I had to sleep sitting up because it just hurt too bad to sit up after laying down. They were super sensitive for a long time but eventually went back to normal. I have never had any problems. I am thinking about having them re-done because they have deflated a little over the years. If I get it done again I will go up to a D. I don't regret having it done and don't have any problems fitting into dresses, bathing suits, etc. I'd do it again in a second.