I can understand your concern.
Tetanus toxoid booster gives immunity for upto 5-6 years.
And tetanus toxoid should be taken within 6 hours of getting injured.
Getting cut by knife would not give you tetanus, it's very less likely that you get tetanus by using a domestic knife.
Anyways, I would suggest you consult a physician in person and till then take a tab. Aceclofenac 100mg twice a day after food.
If it still persists, consult a physician soon.
Dr. Anil Kumar Jain.