My employer told me that I have to get a return to work doctors order, even though I haven't taken any time off sick. I worked over 45 hrs this week. 40 of which are my scheduled hours.
She did this when I said that I didn't feel well enough to come in and cover an extra shift for today, Saturday. I was not scheduled to work it and I have been experiencing a cold all week.
Employers are worried about the flu, so you should just ask your doctor to write you a note. Good luck!