This is a very difficult question to answer without being able to examine you.
It is not uncommon for there to be a superficial wound healing problem after a breast lift. Sometimes, this means that a small area of the incision opens up slightly and takes longer to heal. A lot of patients may think it means there is a bad infection there. Sometimes, there is not.
A bad infection is usually characterized by redness and swelling throughout the entire breast, constant pus coming out from the wound, a large opening of the wound, pain and fever.
My guess is that you probably have a superficial wound healing problem. Although it will take longer to heal, and the scar may end up a little unsightly, everything should turn out fine.
If you develop redness throughout the breast, pain,and or fever, then you should seek immediate medical help, such as going to the emergency room of a nearby hospital.
I also suggest you have frequent follow up with your surgeon and keep him/her informed of your progress.