I accidentally shaved my scrotum with a rusty razor, sadly i only noticed the rust after i shaved but didnt received no cuts from the shave or at least didnt feel anything or see blood. what do i do?

I assume that you've had a tetanus booster within 10 years. Nevertheless this is a low likelihood scenario if you're concerned about tetanus as there was no skin puncture wound. Other skin complications also are unlikely here. Pain& redness would raise concerns about infection. Wash the area and apply an antibacterial ointment.

Nothin except keep area clean and try clipping instead of shaving for the latter is hard to do. The myths about a 'rusty' nail or razor are just myths. Besides a razor should not rust unless ancient