How come I don't feel sore after my workouts?

I've been exercising for 2 weeks and I'm now doing 2-3 sets of 15-20. I don't feel after I exercise. Do I still build muscle? I only have a set of 20 lb dumbbells, an e-z bar with extra weights, and a barbell with extra weights. I mostly use the dumbbells to stabilize my arms and as well for increasing strength.