This sounds quite serious and I strongly suggest that you get this checked out immediately by a doctor
When the integrity of the skin is broken, such as by a cut or gash, this allows bacteria in the dirt and environment get into the wound. These bacteria can set off a serious infection. Some minor cuts do not require medical attention, as they can be simply cleansed out and managed by close observation and by applying antibacterial ointment.
However, if you think the area is infected and if it is developing a smell, then those are bad signs that an infection is progressing. Other worrisome signs would be redness, pain, and warm of the skin surrounding the cut and pus emerging from the wound. All of these would be consistent with a degree of infection that you would not be able to manage on your own.
If there is rapidly spreading redness and worsening pain, or fever
, these are signs that the infection is progressing quite rapidly, and you should go immediately to an emergency room for urgent evaluation and treatment. If the redness is minimal and is not spreading or associated with fever, then you can contact your doctor first for advice.