When can I stop worrying about my nose being bumped?

Slight bumps to the nose in the first few months after a rhinoplasty procedure should not be any problem whatsoever. A significant hit to the nose can be problematic, and that would be very painful, and you would also notice an obvious change in the nasal structure.

I suggest you follow up with your provider regarding postoperative instructions.
Each provider will have their own view on this.
Healing gradually strengthens and by six weeks, things are usually pretty stable.
It is highly unusual for someone to damage surgical outcomes by normal daily activities.
Most people are more conservative than they need to be though people should definitely be careful, especially during the first few weeks.
The only times I’ve had to redo surgery because of physical activity is after suturing infants or young children who had facial lacerations.
Best,
Mats Hagstrom MD