Taking a day off - even knowing you're goin to take a day off is medicinal
Take it from someone who takes em from time to time. Teachers are allowed 20 days per year (based on 2 days for each menstruation cycle). We don't take em all (most I ever took in a year is 15 or 16), but I've always taken at least a couple every year.
Always seems like I'm sicker the day before I stayed home!