Hi Janne,
Chemo has not been too bad at all. Dont be afraid! For me it was like having a bad (prolonged) flu. The specific side effects will depend on the exact chemo drugs given. I have lost my hair, and had fatigue/constipation, but no nausea or vomiting.
The reason they recommended chemo for me is that my cancer was grade 3 which is fast growing. I think they also took into account my age which is young in breast cancer terms. Nevertheless, before reaching that recommendation about my treatment they also considered an option which did not include chemo (monthly injections for three years!). Depending on your pathology, there are options!
Dont stress too much about it - just get through the surgery and after that you will all know more and be able to research and ask questions.
Fiona