What's causing pain under breast implant years later?

(surgery was 20177) What would cause pain under the implant, especially while laying on it on my side? Right out of surgery , i had sharp pains in the breast. Still years later i have pain under it, it will hurt to do arm exercises with weights, & i always need to wear a bra unless i can feel pains. I went to a plastic surgeon recently and she said it looks fine, no capsule contracture etc. And didnt care to investigate furthur.