I think a bit of overreaching (which is what you did) is a good thing, that's how you introduce training stress that causes the body to adapt and become fitter. Just make sure the blocks of training that result in over-reach are balanced with some recovery (which doesn't have to mean complete inactivity, just backing off the intensity/volume a bit for a day or two can be sufficient).

I think "overtraining" has become a bit of a bogeyman that people worry too much about, and even use as an excuse to not push themselves to train harder. Full-blown overtraining (the kind that trashes your endocrine and immune systems) is something that happens over a period of months, not a week or two.