Sometimes i have sharp pain right in the middle to the front of my foot, it hurts as those there is a piece of bone rubbing under my foot, what is it?

Synovitis: I can think of inflammation in one of the joints in the ball of your foot as the most likely cause. Duration, wether you are better in shoes or not, and the type of pain are also helpful in making the diagnosis. You should contact your orthopaedic surgeon to be sure.

Possibly metatarsal: Metatarsalgia is pain on the bottom of the foot near the toes. It can be caused by tight calves, hammertoes, and sometimes a bunion. Shoewear changes can help.

Rule out neuroma: If there is sharp radiating pain in the ball of the foot near the base of the third and fourth toe this could be a neuroma. A neuroma would also feel worse with tight dress shoes and most people notice relief when they take their shoes off and rub the area. Your podiatrist would easily check for a mulder's sign.