In all likelihood under the presumed employer employee handbook that you have with your employer those accrued and earned vacation days and sick days can be applied to cover the 12 days that you are short for qualifying for your desired FMLA leave based upon my experience in such matters. I would speak with your supervisor about taking your vested vacation days and then after such have run, consider some sick days to trigger the FMLA eligibility.Before doing so, I suggest that you consult with an attorney that practices in the area of employment law to make sure your tactics have legal merit.