I had septoplasty 3 weeks ago. A piece of my lower cartilage was removed. Is it ok now to go go for a sauna?

Thanks for sharing your question and photos. You do have clear nasal deformities in your pictures that will need surgical correction to address. Your nasal breathing should significantly improve with a combined septoplasty/rhinoplasty (septorhinoplasty), but some of the other issues...

It is still very early in the healing process so this could potentially be temporary swelling.  Swelling can take a full 6-12 months after surgery.  If the bump persists, you should discuss with your surgeon. 

If you are a week out after your septoplasty, things should be pretty stable at this point and a broken suture should not cause any significant issues. The one exception would be if you have splints that are sutured in the nose and this was the suture holding them in place, they may be mobile...

I'm really sorry to hear about your nosebleeds! They can be caused by any number of things but, in your case, surgery is probably not at fault, not this far out. I would certainly recommend a follow up with the ENT to see if you need something cauterized. The best thing you can do is keep your...