I cut my self deep with the razor and been treatin the wound with polysporin+gauze+alcohol and it look like it has pus. how do i know it infect?

Pus: Pus is usually an indication of bacterial infection. You may need an antibiotic and should be updated on tetanus. Please see your physician. Recover well!

Pus = infection: If a wound looks like it has pus, it's infected until proven otherwise. Once it's infected, it's definitely time to go see your doctor or nearest urgent care. You'll need to get wound cleaned out and possibly some antibiotics, too. Don't wait for infection to get into your blood stream and make you too sick to search healthtap.