Chin lipo 5 months ago. Uneven fat pocket? Or swelling?

You should see the original plastic surgeon to assess the area and discuss your concerns. Once you have spoke to the original surgeon you can seek out another board certified plastic surgeon for a second opinion / assessment. It is hard to tell from the photos and without a physical examination if the area is fat, skin or a possible lipoma/cyst. If the area is fat you can have additional liposuction to remove it without causing excessive scar tissue.