Everyone's advice above is solid- more of a mix of shorter rides with less emphasis on long rides, three days off is a lot. Also important are things you didn't mention- what you do to recover, how hard you've trained coming into this week (whether you've had adequate rest/recovery), your age, your gender, your atheletic history, how well you absorb training volume, whether you are dieting/have positive vs negative calorie balance, adequate protein intake, etc.

But the bottom line for me personally: I just don't sweat a single bad day. It happens, sometimes inexplicably. I get more concerned if I see a trend of multiple bad days.