I don't think an infection is what many people have for a reaction, but I have heard of it during treatment. I would do what your Dr says.
Check out this thread below, it is like a big book of many different peoples experiences during treatment and post-treatment. It is in this same forum, and has been going for a couple years. There are just under 600 posts so far; a lot of caring people all going through the same pain. It helped me get through my rough treatment.
http://www.cancercompass.com/message-board/message/all,4537,