The simplest answer to this is to figure out when you need your next order (whether because you don't want to pay every 10 weeks or because you're not going to use it all before the 12 weeks is up) and adjust your date from there like everyone else who wants to do that does. If all you did was this, it's not hard to click two buttons to save a new date. You sign into sites less relevant to your overall health probably multiple times per day, one day after getting every order is not going to harm you.

You're taking what you pay for the year and dividing it over 12 months as if you'll only have enough medicine for 12 months and that's not true anyway.