Hi, i have a small (penny sized) lump on the top both my feet, underneath the start of the second toe. it feels mainly like hard skin. ?

Underneath=Callus: I believe you are referring the area under the foot at the base of the 2nd toe. This indeed sounds like a callus which is an accumulation of dead skin. This becomes hard and dense from the impact of weight bearing. This area under the 2nd toe is a fairly common location to get one. One gets this from being active and also shows there is some weight transfer to this area away from the big toe.