I came down with Shingles. Out of work for 5 days. Job didnt pay me. Is that legal?

I came down with a case of Shingles, and even though my doctor told me that as long as I wear long sleeve shirt, I could not infect anyone at my office. I told my job this, and they still told me I was not able to return to work until I got a note from my doctor saying I was no longer contagious. 5 working days went by before I was able to return to work, and I supplied my job with a note from my doctor. Today I received my paycheck for that 2 week period, and I see I was only paid for one week. I asked my job about it and they said, because I have yet to accrue the amount of time I was out, I did not get paid. So my question to you all is, Is that legal? I mean I was more than able to come in, they told me not to... Why should I get penalized for being sick? It is not something I planned. So is this legal???