While it is too early to judge the final appearance of a post rhinoplasty nose at 3 weeks, in your case it is obvious that your observations correct. Warping of the septum is a common complication of rhinoplasty, and generally requires re-operation after healing is complete. You should discuss this problem with your surgeon, and makesure he is trined and qualifed to do a secondary revision
Unfortunately this is not normal and you should discuss it with your plastic surgeon. Sometimes swelling can make the nostrils different but it seems that your tip is rotated to the left also Your surgeon would be the best judge of what is going on.