Yes... You need to get back to the gym and work out some more. That will increase the blood flow in your sore muscles and make them feel better. When you work out hard.... you basically tear your muscles... when they heal they are bigger. Basically. That is why you are working out anyway, isnt it?
depends on how strenuous of a workout you did. also if you haven't worked out for a long while you will be sore for a few more days. i pulled out some of my brothers old body building workouts a week ago and i just got over the soreness yesterday.