Hiya. I'll prefix this and say my wife doesn't have CP. 

There's different chemo for different types. Plus, not everyone that gets a BC diagnosis even gets chemo. Which type, if any is to be given, all depends on a number of factors. How extensive the cancers is, which type of BC it is, the aggressiveness, etc etc.

Even those on the same chemo have different experiences. It's an individual thing. One of the types my wife was on, she had a very rough time on it, yet there are other women who have nowhere near the same experience as she did.

IF, and it's a bif "if", she does get the dreaded news, the best person to ask is the oncologist. They specialise in chemo drugs. It's what they do (well, there are different kinds of oncologists, but most do). The nurse(s) you get assigned are also very knowledgable. 

As Jenn stated above, most lumps come back as benign.