I as ENT surgeon would suggest "NO".
see the issues are---
The place you are getting it pierced as absolute sterlization is required as you are piercing the septum--it may bleed and lead to blood collection secondly if later it gets infected or during the procedure it gets infected then you may cartilage injury
and may cause deformity
Secondly the most important area septal angle which is responsible for breathing ie the upper part of area between the septum of nose and lateral wall which is visible or where you normally get pierced .If because of the bar it gets narrowed which will surely happen and because of the bar itself, you may feel like nasal blockage.
And If you later remove the bar then there may be hole in the septum which may give a whistling sound when ever you breath as the air will pass through the hole .