Unlike the flu, chicken pox, or a cold, cancer is not something that you can get just by being around someone who has it. It is something that happens inside of us. Just because you have it does not mean that anyone else you know will. That's the funny thing about cancer - sometimes you can seem perfectly fine, not even a runny nose, but your insides are very sick. But, other times you can be very sick and you don't even know why.
Cancer affects each person differently and usually in a lot of different ways at different times.
There are going to be times when you are going pretty well, not very sick at all. But there are going to be other times when you are going to be very sick and feel very yucky. I have found, as I am sure you know, that after surgery you tend to hurt a lot, and you are usually pretty sick from all the stuff they do to you during surgery. But eventually that gets better as you start to recover a little. During treatments you can be sick for lots of days in a row.