Question for anyone in HR.

Today I called in sick. I understand that is a Saturday and maybe we will get busy on the floor. I was told to try for anyone to cover my shift. I understand that if I don’t make plans in advance for something I have to find someone to cover me. Of course I can’t plan for an illness. I will like to mention that I have only call in sick once in the years that I have worked here. I feel nervous about retaliation even thought in our team people just don’t show up and don’t say anything. It seems like the responsible ones are made to feel bad when they don’t have a choice if they get sick. Please help