I have clusters of red dots on lower legs & feet, worse on left leg. doesn't dissappear, doesnt itch & is not raised, just there. what could it be?

One look is worth a: 1000 words. A broad differential would be; bug bites of some type, a viral rash, some broken blood vessels, contact dermatitis from some plant, localized allergic reaction. If they cause you no symptoms it is probably safe to watch for 7-10 days and see if they go away. You could also try to use an over the counter steroid cream.