Many surgeons will wait 3 to 6 months to make sure the tissue has healed and settled down before inserting a new implant. If one breast is doing well with its implant, you might want to just let it heal. However, if being uneven is a big concern, you might ask to remove the other implant. I prefer to keep the noninfected implant since this will decrease the number of surgeries you will have.
Implant needing removed - 8 weeks post BA
In my practice we wait 10 - 12 weeks after taking out an infected implant before replacing it. Normally we would want to put the same size back in as long as it was a reasonable size.