I have a hard bump at the top of my butt. it's sore to the touch and if i move or sit a certain way it's very painful. any idea what it could be?

Could be infection: Sounds like this could be an abcess, which is a collection of pus under the skin, or depending on where it is above your butt, an infected pilonidal cyst. Either one requires attention becasue if there's a lot of pus in there, it needs to be drained and/or antibiotics given. See doc tomorrow, or today if one available.. Put warm compresses on in meantime.