Will this small bump 3 weeks after rhinoplasty go away on its own? (Photos)

Thank you for your question and sharing your photos.
     There is no way to know if the bump you are concerned about is caused from the trauma of surgery and will eventually smooth out or if it was there before your surgery.    Concerns such as this should definitely discussed with your surgeon.  If they know you are worried, they can address the situation and hopefully give you some reassurance.  Most importantly,  don't be discouraged.  After rhinoplasty surgery, it can take several months for all of the swelling to subside so that you can see the final result.    It is very likely that you will see a lot of changes in the coming months.  
Best Wishes,

Hi and welcome to our forum!
The performance of rhinoplasty involves the dissection of the nasal
bones and cartilages from overlying and underlying structures, fracturing
the nasal bones, removing excess bone / cartilage, reshaping of the
remaining bone and cartilage. The significant intraoperative trauma
causes swelling (which may be asymmetric), which will make your nose look
large and wide and areas of localized swelling may resemble residual anatomic structures. This will improve markedly over the first 6 weeks, but will
take at least a year for your nose to assume its final shape and size. Only after healing can one discern if a secondary touch up is required. 
Continue followup with your surgeon.
Best wishes...