My big toe has had a slight numbness for the last couple of days and i don't know why?

Could be tight shoe: If the numbness is on the outside of the toe it is probably due to compression of the nerve from a tight shoe.

I would look: And see if you were wearing tight shoes, have an ingrown toenail, have any low back pain/problems as this could cause big toe numbness, or compression of the deep peroneal nerve at the base of the first intermetatarsal base.