Am I lifting weights right if I'm not sore after it or the next day?

If you are doing the same thing for days at at a time then chances are that your body IS getting used to it and you aren't getting sore. Also, you don't always have to be "sore" to get a good workout. It might seem as though thats the case, but its not. It is a good idea to change up your routine often though. Idk if you've heard of P90X but the reason its always successful is because your body is never able to get used to the workouts so it CONTINUOUSLY keeps getting stronger in every way possible. Your body is never able to adapt to the workouts so its constantly has to get stronger.