It's all really variable - plan for the worst but hope for better things. I was one of the lucky ones - I did have side effects, but not fatigue or nausea. I worked through 6 months of chemo - not brave, just not sick. Even in an open plan office, I didn't catch anything. Blood count remained fine throughout. The first two or three weeks will give you a better idea. As everyone says, if you do have difficult side effects, you are still likely to have better and worse days and can plan a little bit accordingly. It can seem like treatment will go on for ever at the beginning, but it does pass. Best wishes.
