I believe this is commonly referred to as an "unfortunate coincidence"

When the 10 day plan of reducing meds results in the one day of ‘clear out’ – meaning no meds – arrives on Day 3 coupled with a gall bladder flare-up, the like of which I haven’t had for about 2-3 weeks and two little boys intent on playing with the same car come hell or whoever screams the loudest.