Yes. You need to follow your department’s call-in procedures (e.g., when to call, whom to call) for intermittent or unplanned absences. If you do not know those call-in procedures, ask your supervisor. You will need to report the leave as FML related in order for it to be coded FML in your attendance records.
No, you do not need new medical certification of the condition that causes the intermittent absence if that condition has already been approved. However, it may be necessary to document the reason for the absence; that is, that you were absent that day for the FML reason and not some other reason.
Yes. Your supervisor has an obligation to accurately track your absences. Your supervisor can ask you for information necessary to determine whether the absence is covered by FMLA. You have an obligation to respond to those questions. Your supervisor may not ask specific questions related to the medical condition.
You must work with your department and make a reasonable effort to schedule the planned appointments at a time that will not disrupt the work of your department.