You should express your concerns with your plastic surgeon to discuss the issue but more time will be recommended to allow for swelling to go down before any revisions can be done.
In my opinion, it is a little premature to perform an alar base reduction 5 weeks after having a rhinoplasty. You can expect some noticeable changes over the next several weeks.
I would discuss your concerns with your surgeon and see when he/she feels it's appropriate to pursue an alar base reduction. This sometimes can be performed in the office under local anesthesia.
Alar base resections can help to reshape and refine the nostril. These can be performed during the rhinoplasty or staged after the procedure. Alar base resections can narrow the nostrils and make them smaller. It does require an incision along the base of the nose and can be performed under local anesthesia. Alar base resections can be performed at the earliest at the 6 week point, but more accurately at the 3 month point.
narrowing of the alar base or nostril can be performed following rhinoplasty, but I would recommend waiting at least 3 months to allow some swelling to resolve. The results of your surgery will take several years to become completely visible, so don't rush, and I would agree that speaking with your surgeon about this is the first best step.
Your tip is still coming down which will change the appearance of the nostrils. Talk to the surgeon who did your surgery. You can do the procedure now. Some surgeons will do it under local anesthesia in the office.