Your problem is a very common one for women with a T-shaped incision for breast reduction or lift. The problem is that this part of the incision is the furthest from the blood supply that brings nutrients to the wound to enable it to heal. Except for a little redness (inflammation), your wounds do not appear to be infected. However the best way to tell is with a wound culture. If the incision has been open more than 2 weeks, then the risk of infection rises unless excellent care is administered.
Especially since you have implants inserted behind the incision, an infection would be a disaster. You are correct to worry about it, and your surgeon should be more worried, and keep close watch on the progress of your healing. A second operation to excise the wound edges, and reclose the wound would not be a bad option.
Thank you for your pictures. This is not infected. It looks like you have wound breakdown. The unhealthy tissue may need to be cleaned and daily dressings may be used to affect healing. Please discuss with your plastic surgeon the best regimen of local wound care to affect healing.
Appears as slow healing in your case. But you deserve informed responses to all your concerns. Who was your surgeon??