I have a small cut on my left hand index finger, the cut is not so deep and didn't bleed, but whenever I wash my hand or wash cloths I feel sourness in the cut part, so today as the rain was heavily poured down I was holding an umbrella, the rod of the umbrella is little rusted and with the rain water it turns into brownish water and it all over splash on my cut part, I wash my hand with soap and dettol afterwards, so do I need to take a tetanus injection for this, but last time I took tetanus injection was 2 months back due to an injury, so what shall I do?