Is it bad to run every weekday?
3-4 days per week is the conservative recommendation for beginners, but if you're currently doing 5 and feel fine, I don't see a problem. Just watch out for signs of overtraining, such as trouble catching sleep, sudden drop in performance, aberrant heart rates, general grogginess, etc.
How many days a week should I run?
Typically, beginners should aim to run (or run/walk) about three days per week. If you run more than this, you risk getting injured. If you run less than this, often you will not develop your aerobic or muscular systems as effectively as you could.