You don't have to point anything out to your boss because he is the boss and is suppose to know the law. The medical certificate should have a date on it declaring what day you are suppose to be off work. Be sure to take note if it states anything less than 100%, if it says (for example) 50% then you still have to work half days until your doctor says otherwise. My X had a month or so of 50% then in her 8th month the doctor increased it to 100%.