Why is my nostril becoming 'pinched'/triangular post Rhinoplasty? (photos)

I had a septo-rhinoplasty 6 weeks ago abroad and over time my right nostril has become 'pinched' or triangular in shape. When the cast first came off it didn't look too pinched/triangular and was barely noticeable but over the weeks it is getting worse. How likely do you think this is due to swelling and will go away? Are there any massages or anything else i can do to stop it from getting worse? I do not want to undergo anymore surgery so perhaps a filler after 6 months might help?