Am I Overtraining?

So I woke up Friday morning with all the beginning signs that I am getting sick. For me, it starts with a sore throat and a headache that I am sure will turn into sinus pressure. Neither was too bad, but I just didn't feel right. I had thought that I had been fighting something for a couple of days because I had felt a bit worn down. Now I was pretty sure that I was coming down with something.
I haven't been sick in almost a year. I mean nothing really bad; that is pretty good for me. I used to work with kids and, at least my husband would say, I was sick all the time. Interpretation: three or four times a year. Not all of these were bad enough to warrant a trip to the doctor, but each took me out of commission to a point. This is where I should probably mention that, again by my interpretation, I have some OCD tendencies. I have never been diagnosed with obsessive compulsive and it doesn't come down to having to wash my hands three times or flip switches X number of times. It is just little stuff. For example, I hate missing work. I will take time off to go on trips (it is pretty easy with my current job), but if I am not feeling well, I will most likely still be working. I don't have a physically taxing job. I can do my job when I am ill almost as well as I can do it when I am well. Of course if I stay home, I can't do it at all. I also hate missing work outs, this was true even before I started riding. If I don't have the time at all that is understandable. But to have the time and not do it, that I just struggle with. I usually talk my self into the fact that I am being a wimp and just go do something, even if it in nice and easy. In my defense, I have also read that working out can have benefits when you are feeling under the weather. I tend to feel better if I have done some nice easy cardio versus just sitting around.
Needless to say I was talking to a friend who accused me of over training. Me? Overtraining? My first thoughts were it is winter, how could that even be possible? I have been putting in 10-12 hours week, which is not that much. My reply was that being sick is not always an indication that an individual is overtrained. After all, sendentary individuals get sick. They do no training. Then post conversation I thought some more about it. Do physically active individuals get sick if they are not overtraining? Exercise has been proven to build the immune system. But exercise also decreases some immune cells which are key to the immune response. Usually the body can balance these, but if the immune system is put into the defense mode, does that mean it has been doing too much? Now I am not so sure.
Well, I did leave work early and I took a nap. I never take naps, unless I don't feel well. I hate them. To me they are a sign of laziness and time ill spent. Yes, I have also heard that sleep is the time the body repairs itself and athletes need more rest because they cause their bodies more trauma. I did feel better after my nap. It made me miss Oprah though.
Sites on overtraining:
http://www.rice.edu/~jenky/sports/overtraining.html
http://www.pponline.co.uk/encyc/0213.htm