When I get my refill, I take a months worth and put it in a separate bottle. When I get down to about a weeks worth, in the main bottle, I set up an appointment. Because the receptionists normally handle prescriptions, I suspect I could ask them to see if I can get a refill to hold me over but so far it hasn't reached that point. My old endo would always round the prescription up - 90 day supply would be 100 tablets. With that system I could always set up my appointment months in advance exactly on the 3 or 6 months time period. Because I am now getting a 180 day supply, the schedule needs to slip a little bit each time.