No.  Under the FMLA, you are simply entitled to take up to 12 weeks unpaid time off within the 12-month period, whether all at once or intermittently.  For example, in cases where an employee is diagnosed with cancer that requires chemo treatment, that employee may need to take a few days off at a time in order to receive the treatment and recover from the side effects.  This is entirely permissible under the FMLA. Additionally, the 12-month period need not be an actual calendar year, but can begin on the date when you began taking FMLA leave.