Everyone's body is different. If you get something pierced and someone else gets the same piercing, your results could be the same or they could be unique. You should never take out a fresh piercing at three days, this is far too soon to be messing with your piercing. Noses (nostrils) take between two to four months to completely heal, and even then some people are going to have issues with pain, especially if they've never left the jewelry in long enough to heal properly. You might want to go back to a piercer and have them look at your nose to make sure there's nothing keeping it from healing, and it might heal easier with a ring in instead of a stud.